292
Anti-Self-Dual 4-Manifolds, Quasi-Fuchsian Groups, & Almost-K¨ ahler Geometry Claude LeBrun Stony Brook University Conformal and Symplectic Geometry University of Auckland, 7 February, 2018

Anti-Self-Dual 4-Manifolds, Quasi-Fuchsian Groups, & Almost-K …claude/auckland.pdf · Anti-Self-Dual 4-Manifolds, Quasi-Fuchsian Groups, & Almost-K ahler Geometry Claude LeBrun

Embed Size (px)

Citation preview

Anti-Self-Dual 4-Manifolds,

Quasi-Fuchsian Groups, &

Almost-Kahler Geometry

Claude LeBrunStony Brook University

Conformal and Symplectic GeometryUniversity of Auckland, 7 February, 2018

1

Most recent results joint with

2

Most recent results joint with

Christopher J. BishopStony Brook University

3

Most recent results joint with

Christopher J. BishopStony Brook University

e-print: arXiv:1708.03824 [math.DG]

4

Most recent results joint with

Christopher J. BishopStony Brook University

e-print: arXiv:1708.03824 [math.DG]

To appear in Comm. An. Geom.

5

Themes of this conference:

Conformal Geometry

Almost-Kahler Geometry

Symplectic GeometryJJJJJJJJJJJJJJJJJJJJ]

��

-�

6

Theme of this talk:

Conformal Geometry

Almost-Kahler Geometry

Symplectic Geometry

7

Theme of this talk:

Conformal Geometry

Almost-Kahler Geometry

Symplectic GeometryJJJJJJJJJJ JJJJJJJJJJ]

-�

8

Theme of this talk:

Conformal Geometry

Almost-Kahler Geometry

Symplectic GeometryJJJJJJJJJJ JJJJJJJJJJ]

-�

Talk concerns phenomena specific to dimension 4.

9

Theme of this talk:

Conformal Geometry

Almost-Kahler Geometry

Symplectic GeometryJJJJJJJJJJ JJJJJJJJJJ]

-�

Talk concerns phenomena specific to dimension 4.

Higher dimensions are demonstrably different.

10

Let (M2m, ω) be a compact symplectic manifold.

11

Let (M2m, ω) be a compact symplectic manifold.

12

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

13

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

14

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

15

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

16

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

17

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

18

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

19

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

Leads to theory of J -holomorphic curves,

20

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

Leads to theory of J -holomorphic curves,Gromov-Witten invariants, etc.

21

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

Leads to theory of J -holomorphic curves,Gromov-Witten invariants, etc.

Imitates Kahler geometry in a non-Kahler setting.

22

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

23

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

=⇒ g := ω(·, J ·) is a Riemannian metric.

24

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

=⇒ g := ω(·, J ·) is a Riemannian metric.

Such g are called almost-Kahler metrics, because

25

Let (M2m, ω) be a compact symplectic manifold.

Thus, ω is a 2-form with dω = 0 and ω∧m 6= 0.

By convention, orient M so that ω∧m > 0.

⇒ ∃ compatible almost-complex structures J :

J : TM → TM, J2 = −1,

J∗ω = ω, ω(v, Jv) > 0 ∀v 6= 0.

=⇒ g := ω(·, J ·) is a Riemannian metric.

Such g are called almost-Kahler metrics, because

Kahler ⇐⇒ J integrable.

26

Discussion involves three intertwined structures:

27

Discussion involves three intertwined structures:

J

g

ωJJJJJJJJJJJJJJJJJJJJ]

��

-�

28

Discussion involves three intertwined structures:

J

g

ωJJJJJJJJJJJJJJJJJJJJ]

��

-�

Any two algebraically determine the third.

29

Discussion involves three intertwined structures:

J

g

ωJJJJJJJJJJJJJJJJJJJJ]

��

-�

Any two algebraically determine the third.

For example, can avoid explicitly mentioning J .

30

Discussion involves three intertwined structures:

J

g

ωJJJJJJJJJJJJJJJJJJJJ]

��

-�

31

Discussion involves three intertwined structures:

g

ω

��

32

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒

33

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒

34

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒

35

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒

36

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√m,

37

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√m,

• dω = 0, and

38

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√m,

• dω = 0, and

• ∗ω =ω∧(m−1)

(m− 1)!.

39

Discussion involves three intertwined structures:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√m,

• ω is a harmonic 2-form, and

• ∗ω =ω∧(m−1)

(m− 1)!.

40

Simplifies dramatically when m = 2:

g

ω

��

Lemma.An oriented Riemannian manifold (M2m, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√m,

• ω is a harmonic 2-form, and

• ∗ω =ω∧(m−1)

(m− 1)!.

41

Simplifies dramatically when m = 2:

g

ω

��

Lemma.An oriented Riemannian 4-manifold (M, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√2,

• ω is a harmonic 2-form, and

• ∗ω = ω.

42

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

43

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

Λ+ self-dual 2-forms:(+1)-eigenspace of ∗ : Λ2→ Λ2.

44

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

Λ+ self-dual 2-forms:(+1)-eigenspace of ∗ : Λ2→ Λ2.

Λ− anti-self-dual 2-forms:(−1)-eigenspace of ∗ : Λ2→ Λ2.

45

Simplifies dramatically when m = 2:

g

ω

��

Lemma.An oriented Riemannian 4-manifold (M, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√2,

• ω is a harmonic 2-form, and

• ∗ω = ω.

46

Simplifies dramatically when m = 2:

g

ω

��

Lemma.An oriented Riemannian 4-manifold (M, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√2,

• ω is a self-dual harmonic 2-form.

47

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

Λ+ self-dual 2-forms:(+1)-eigenspace of ∗ : Λ2→ Λ2.

Λ− anti-self-dual 2-forms:(−1)-eigenspace of ∗ : Λ2→ Λ2.

48

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

Λ+ self-dual 2-forms:(+1)-eigenspace of ∗ : Λ2→ Λ2.

Λ− anti-self-dual 2-forms:(−1)-eigenspace of ∗ : Λ2→ Λ2.

But Hodge star

∗ : Λ2→ Λ2

is conformally invariant on middle-dimensional forms:

49

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

Λ+ self-dual 2-forms:(+1)-eigenspace of ∗ : Λ2→ Λ2.

Λ− anti-self-dual 2-forms:(−1)-eigenspace of ∗ : Λ2→ Λ2.

But Hodge star

∗ : Λ2→ Λ2

is conformally invariant on middle-dimensional forms:

Only depends on the conformal class

[g] := {u2g | u : M → R+}.

50

On oriented (M4, [g]),

Λ2 = Λ+ ⊕ Λ−

Λ+ self-dual 2-forms:(+1)-eigenspace of ∗ : Λ2→ Λ2.

Λ− anti-self-dual 2-forms:(−1)-eigenspace of ∗ : Λ2→ Λ2.

Only depends on the conformal class

[g] := {u2g | u : M → R+}.

51

Simplifies dramatically when m = 2:

g

ω

��

Lemma.An oriented Riemannian 4-manifold (M, g)is almost-Kahler w/ respect to the 2-form ω ⇐⇒• |ω|g ≡

√2,

• ω is a self-dual harmonic 2-form.

52

Simplifies dramatically when m = 2:

[g]

ω

��

Proposition.A conformal class [g] on a smoothcompact oriented 4-manifold M is represented byan almost-Kahler metric g iff it carries a self-dual harmonic 2-form ω that is 6= 0 everywhere.

53

Simplifies dramatically when m = 2:

[g]

ω

��

Proposition.A conformal class [g] on a smoothcompact oriented 4-manifold M is represented byan almost-Kahler metric g iff it carries a self-dual harmonic 2-form ω that is 6= 0 everywhere.

Moreover, the set of conformal classes [g] on Mthat carry such a harmonic form ω is open inthe C2 topology.

54

Hodge theory:

H2(M,R) = {ϕ ∈ Γ(Λ2) | dϕ = 0, d ∗ ϕ = 0}.

55

Hodge theory:

H2(M,R) = {ϕ ∈ Γ(Λ2) | dϕ = 0, d ∗ ϕ = 0}.Since ∗ is involution of RHS, =⇒

H2(M,R) = H+g ⊕H−g ,

56

Hodge theory:

H2(M,R) = {ϕ ∈ Γ(Λ2) | dϕ = 0, d ∗ ϕ = 0}.Since ∗ is involution of RHS, =⇒

H2(M,R) = H+g ⊕H−g ,

where

H±g = {ϕ ∈ Γ(Λ±) | dϕ = 0}self-dual & anti-self-dual harmonic forms.

57

Hodge theory:

H2(M,R) = {ϕ ∈ Γ(Λ2) | dϕ = 0, d ∗ ϕ = 0}.Since ∗ is involution of RHS, =⇒

H2(M,R) = H+g ⊕H−g ,

where

H±g = {ϕ ∈ Γ(Λ±) | dϕ = 0}self-dual & anti-self-dual harmonic forms.

One can choose a basis for H±g that depends

continuously on g in the C1,α topology.

58

Simplifies dramatically when m = 2:

[g]

ω

��

Proposition.A conformal class [g] on a smoothcompact oriented 4-manifold M is represented byan almost-Kahler metric g iff it carries a self-dual harmonic 2-form ω that is 6= 0 everywhere.

Moreover, the set of conformal classes [g] on Mthat carry such a harmonic form ω is open inthe C2 topology.

59

Simplifies dramatically when m = 2:“Conformal classes of symplectic type”

Proposition.A conformal class [g] on a smoothcompact oriented 4-manifold M is represented byan almost-Kahler metric g iff it carries a self-dual harmonic 2-form ω that is 6= 0 everywhere.

Moreover, the set of conformal classes [g] on Mthat carry such a harmonic form ω is open inthe C2 topology.

60

Hodge theory:

H2(M,R) = {ϕ ∈ Γ(Λ2) | dϕ = 0, d ∗ ϕ = 0}.Since ∗ is involution of RHS, =⇒

H2(M,R) = H+g ⊕H−g ,

where

H±g = {ϕ ∈ Γ(Λ±) | dϕ = 0}self-dual & anti-self-dual harmonic forms.

One can choose a basis for H±g that depends

continuously on g in the C1,α topology.

61

Hodge theory:

H2(M,R) = {ϕ ∈ Γ(Λ2) | dϕ = 0, d ∗ ϕ = 0}.Since ∗ is involution of RHS, =⇒

H2(M,R) = H+g ⊕H−g ,

where

H±g = {ϕ ∈ Γ(Λ±) | dϕ = 0}self-dual & anti-self-dual harmonic forms.

One can choose a basis for H±g that depends

continuously on g in the C1,α topology.

In particular, the numbers

b±(M) = dimH±gare independent of g, and so are invariants of M .

62

b±(M)?

63

Best understood in terms of intersection pairing

64

Best understood in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

65

Best understood in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

Diagonalize:

+1. . .

+1︸ ︷︷ ︸b+(M)

b−(M)

−1. . .

−1

.

66

Best understood in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

Diagonalize:

+1. . .

+1︸ ︷︷ ︸b+(M)

b−(M)

−1. . .

−1

.

67

Best understood in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

Diagonalize:

+1. . .

+1︸ ︷︷ ︸b+(M)

b−(M)

−1. . .

−1

.

b2(M) = b+(M) + b−(M)

68

Best understood in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

Diagonalize:

+1. . .

+1︸ ︷︷ ︸b+(M)

b−(M)

−1. . .

−1

.

τ (M) = b+(M)− b−(M)

“Signature” of M .

69

Signature defined in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

Diagonalize:

+1. . .

+1︸ ︷︷ ︸b+(M)

b−(M)

−1. . .

−1

.

τ (M) = b+(M)− b−(M)

Signature of M .

70

Signature defined in terms of intersection pairing

H2(M,R)×H2(M,R) −→ R

( [ϕ] , [ψ] ) 7−→∫Mϕ ∧ ψ

τ (M) = b+(M)− b−(M)

71

Signature defined in terms of intersection pairing,

but also expressible as a curvature integral:

τ (M) =1

12π2

∫M

(|W+|2 − |W−|2

)dµ

= 〈p1(M), [M ]〉

72

Signature defined in terms of intersection pairing,

but also expressible as a curvature integral:

τ (M) =1

12π2

∫M

(|W+|2 − |W−|2

)dµ

= 〈13p1(M), [M ]〉

(Thom-Hirzebruch Signature Formula)

73

Signature defined in terms of intersection pairing,

but also expressible as a curvature integral:

τ (M) =1

12π2

∫M

(|W+|2 − |W−|2

)dµ

= 〈p1(M), [M ]〉

Has major consequences in conformal geometry.

74

On oriented (M4, g),

Λ2 = Λ+ ⊕ Λ−

75

Riemann curvature of g

R : Λ2→ Λ2

76

Riemann curvature of g

R : Λ2→ Λ2

splits into 4 irreducible pieces:

77

Riemann curvature of g

R : Λ2→ Λ2

splits into 4 irreducible pieces:

R =

W+ + s

12 r

r W− + s12

78

Riemann curvature of g

R : Λ2→ Λ2

splits into 4 irreducible pieces:

Λ+∗ Λ−∗

Λ+ W+ + s12 r

Λ− r W− + s12

79

Riemann curvature of g

R : Λ2→ Λ2

splits into 4 irreducible pieces:

Λ+∗ Λ−∗

Λ+ W+ + s12 r

Λ− r W− + s12

where

s = scalar curvature

r = trace-free Ricci curvature

W+ = self-dual Weyl curvature (conformally invariant)

W− = anti-self-dual Weyl curvature

80

Riemann curvature of g

R : Λ2→ Λ2

splits into 4 irreducible pieces:

Λ+∗ Λ−∗

Λ+ W+ + s12 r

Λ− r W− + s12

where

s = scalar curvature

r = trace-free Ricci curvature

W+ = self-dual Weyl curvature (conformally invariant)

W− = anti-self-dual Weyl curvature ′′

81

For M4 compact, the Weyl functional

82

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

83

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,

84

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

85

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

86

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

87

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

Basic problems: For given smooth compact M4,

88

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

Basic problems: For given smooth compact M4,

•What is inf W ?

89

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

Basic problems: For given smooth compact M4,

•What is inf W ?

•Do there exist minimizers?

90

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

But we’ve already noted that

12π2τ (M) =

∫M

(|W+|2 − |W−|2

)dµg

is a topological invariant.

91

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

But we’ve already noted that

12π2τ (M) =

∫M

(|W+|2 − |W−|2

)dµg

is a topological invariant.

So Weyl functional is essentially equivalent to

[g] 7−→∫M|W+|2dµg

92

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

But we’ve already noted that

12π2τ (M) =

∫M

(|W+|2 − |W−|2

)dµg

is a topological invariant.

In particular, metrics with W+ ≡ 0 minimize W .

93

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

But we’ve already noted that

12π2τ (M) =

∫M

(|W+|2 − |W−|2

)dµg

is a topological invariant.

In particular, metrics with W+ ≡ 0 minimize W .

If g has W+ ≡ 0, it is said to be anti-self-dual.

94

For M4 compact, the Weyl functional

W ([g]) =

∫M

(|W+|2 + |W−|2

)dµg

measures the deviation from conformal flatness,because (M4, g) is locally conformally flat ⇐⇒its Weyl curvature W = W+ + W− vanishes.

But we’ve already noted that

12π2τ (M) =

∫M

(|W+|2 − |W−|2

)dµg

is a topological invariant.

In particular, metrics with W+ ≡ 0 minimize W .

If g has W+ ≡ 0, it is said to be anti-self-dual.(ASD)

95

Twistor picture of anti-self-duality condition:

96

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

97

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

Z = S(Λ+), J : TZ → TZ, J2 = −1:

98

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

Z = S(Λ+), J : TZ → TZ, J2 = −1:

.....................................................................................................................................................................................................................................................................................................................................................................................................................................

............................

.......................

.........................

.......................................................................................................................................................

.................

.............

..........

......................................

...................................

........................

.................................................................

....................................

r

rr S(Λ+)

M 4

.......................................................................

..................

..................

..................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.............................................................................................................................................................

................. .................

......................................................................................

.......................................................................

............................... ...............................

..................................................................................................................................................

......................................................................................................................

.....................................................

......................................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.........................................................................................................

.............................................................................

...............................................................................................................................................................................................................................................................................................................................................................................................................

99

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

Z = S(Λ+), J : TZ → TZ, J2 = −1:

.....................................................................................................................................................................................................................................................................................................................................................................................................................................

............................

.......................

.........................

.......................................................................................................................................................

.................

.............

..........

......................................

...................................

........................

.................................................................

....................................

r

rr S(Λ+)

M 4

.......................................................................

..................

..................

..................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.............................................................................................................................................................

................. .................

......................................................................................

.......................................................................

............................... ...............................

..................................................................................................................................................

......................................................................................................................

.....................................................

......................................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.........................................................................................................

.............................................................................

...............................................................................................................................................................................................................................................................................................................................................................................................................

Theorem (Atiyah-Hitchin-Singer). (Z, J) is a com-plex 3-manifold iff W+ = 0.

100

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

Z = S(Λ+), J : TZ → TZ, J2 = −1:

.....................................................................................................................................................................................................................................................................................................................................................................................................................................

............................

.......................

.........................

.......................................................................................................................................................

.................

.............

..........

......................................

...................................

........................

.................................................................

....................................

r

rr S(Λ+)

M 4

.......................................................................

..................

..................

..................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.............................................................................................................................................................

................. .................

......................................................................................

.......................................................................

............................... ...............................

..................................................................................................................................................

......................................................................................................................

.....................................................

......................................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.........................................................................................................

.............................................................................

...............................................................................................................................................................................................................................................................................................................................................................................................................

Theorem (Atiyah-Hitchin-Singer). (Z, J) is a com-plex 3-manifold iff W+ = 0.

Reconceptualizes earlier work by Penrose.

101

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

Z = S(Λ+), J : TZ → TZ, J2 = −1:

.....................................................................................................................................................................................................................................................................................................................................................................................................................................

............................

.......................

.........................

.......................................................................................................................................................

.................

.............

..........

......................................

...................................

........................

.................................................................

....................................

r

rr S(Λ+)

M 4

.......................................................................

..................

..................

..................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.............................................................................................................................................................

................. .................

......................................................................................

.......................................................................

............................... ...............................

..................................................................................................................................................

......................................................................................................................

.....................................................

......................................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.........................................................................................................

.............................................................................

...............................................................................................................................................................................................................................................................................................................................................................................................................

Theorem (Atiyah-Hitchin-Singer). (Z, J) is a com-plex 3-manifold iff W+ = 0.

102

Twistor picture of anti-self-duality condition:

Oriented (M4, g)! (Z, J).

Z = S(Λ+), J : TZ → TZ, J2 = −1:

.....................................................................................................................................................................................................................................................................................................................................................................................................................................

............................

.......................

.........................

.......................................................................................................................................................

.................

.............

..........

......................................

...................................

........................

.................................................................

....................................

r

rr S(Λ+)

M 4

.......................................................................

..................

..................

..................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.............................................................................................................................................................

................. .................

......................................................................................

.......................................................................

............................... ...............................

..................................................................................................................................................

......................................................................................................................

.....................................................

......................................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.........................................................................................................

.............................................................................

...............................................................................................................................................................................................................................................................................................................................................................................................................

Theorem (Atiyah-Hitchin-Singer). (Z, J) is a com-plex 3-manifold iff W+ = 0.

Motivates study of ASD metrics,and yields methods for constructing them.

103

So ASD metrics are linked to complex geometry. . .

104

A different link with complex geometry:

105

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD

106

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

107

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

108

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:special case of cscK manifolds,

109

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:special case of cscK manifolds,and so of extremal Kahler manifolds.

110

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:special case of cscK manifolds,and so of extremal Kahler manifolds.

Results proved about SFK in ’90s foreshadowedmany more recent results about general case.

111

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

112

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism: compact case

113

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism: (compact case)

114

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism: (compact case)

115

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

116

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

117

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

118

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

–K3

•Non-Ricci-flat case

119

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

–K3

– T 4

•Non-Ricci-flat case

120

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

–K3

– T 4

– eight specific finite quotients of these

•Non-Ricci-flat case

121

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

–K3

– T 4

– eight specific finite quotients of these

•Non-Ricci-flat case

122

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

123

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

124

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

125

Convention:

CP2 = reverse oriented CP2.

126

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

...........................................................................................................................................................................................................................................................................................................................................................................................................

...........................................................

................... ...........................

................................................................................................................................................................................................................................................................................................................................................................................

.........................

..................................................

...

................................................................................. .....................................................

......................................................................................................................................

127

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

................................................................. ..................................

................................

................................

................................

................................

128

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

129

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

................................................................. ..................................

................................

................................

................................

................................

130

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

...........................................................................................................................................................................................................................................................................................................................................................................................................

...........................................................

................... ...........................

................................................................................................................................................................................................................................................................................................................................................................................

.........................

..................................................

...

................................................................................. .....................................................

......................................................................................................................................

131

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

................................................................. ..................................

................................

................................

................................

................................

132

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

133

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

134

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

Blowing Up: M M#CP2

135

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

136

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

Blowing Up: M M#CP2

137

Convention:

CP2 = reverse oriented CP2.

Connected sum #:

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

..................................

..................................

................................

................................

138

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

139

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

– (T 2 × S2)#kCP2, k ≥ 1

140

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

– (T 2 × S2)#kCP2, k ≥ 1

– Σ× S2

141

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

– (T 2 × S2)#kCP2, k ≥ 1

– Σ× S2 and Σ×S2,

142

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

– (T 2 × S2)#kCP2, k ≥ 1

– Σ× S2 and Σ×S2, genus Σ ≥ 2

143

A different link with complex geometry:

If (M4, g, J) is a Kahler surface, then [g] is ASD⇐⇒ the scalar curvature s of g is identically zero.

Scalar-flat Kahler surfaces:

Classification up to diffeomorphism:

•Ricci-flat case (ignore from now on)

•Non-Ricci-flat case

–CP2#kCP2, k ≥ 10

– (T 2 × S2)#kCP2, k ≥ 1

– Σ× S2 and Σ×S2, genus Σ ≥ 2

– (Σ× S2)#kCP2, k ≥ 1

144

Notice that the 4-manifolds CP2#kCP2

145

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

146

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:

147

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:these manifolds don’t admit any ASD metrics.

148

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:these manifolds don’t admit any ASD metrics.

Stronger conjecture:

149

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:these manifolds don’t admit any ASD metrics.

Stronger conjecture:any metric on one of these manifolds M satisfies∫

M|W+|2dµ ≥

4π2

3(9− k)

150

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:these manifolds don’t admit any ASD metrics.

Stronger conjecture:any metric on one of these manifolds M satisfies∫

M|W+|2dµ ≥

4π2

3(2χ + 3τ )(M)

151

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:these manifolds don’t admit any ASD metrics.

Stronger conjecture:any metric on one of these manifolds M satisfies∫

M|W+|2dµ ≥

4π2

3(2χ + 3τ )(M)

Theorem (Gursky ’98).True for conformal classesof positive Yamabe constant.

152

Notice that the 4-manifolds CP2#kCP2do not admit scalar-flat Kahler metrics when k ≤ 9.

Plausible conjecture:these manifolds don’t admit any ASD metrics.

Stronger conjecture:any metric on one of these manifolds M satisfies∫

M|W+|2dµ ≥

4π2

3(2χ + 3τ )(M)

Theorem (Gursky ’98).True for conformal classesof positive Yamabe constant.

Theorem (L ’15). True for conformal classes ofsymplectic type.

153

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

154

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

155

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

Does this say anything about general ASD metrics?

156

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

Does this say anything about general ASD metrics?

Almost-Kahler ASD metrics sweep out an open setin the ASD moduli space.

157

Example.

Σ

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

158

Example.

Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

159

Example.

M = Σ× S2

Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

160

Example.

M = Σ× S2

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

161

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

162

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Product is scalar-flat Kahler.

163

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Product is scalar-flat Kahler.

164

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Product is scalar-flat Kahler.For both orientations!

165

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Product is scalar-flat Kahler.For both orientations!W+ = 0.

166

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Product is scalar-flat Kahler.For both orientations!W± = 0.

167

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Product is scalar-flat Kahler.For both orientations!W± = 0.Locally conformally flat!

168

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

M = H2×S2= S4 − S1

169

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

M = H2×S2 = S4 − S1

170

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

M = H2×S2 = S4 − S1

π1(Σ) ↪→ SO+(1, 2)×SO(3) ↪→ SO+(1, 5)

171

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

M = H2×S2 = S4 − S1

π1(Σ) ↪→ SO+(1, 2)× SO(3)↪→ SO+(1, 5)

172

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

M = H2×S2 = S4 − S1

π1(Σ) ↪→ SO+(1, 2)× SO(3) ↪→ SO+(1, 5)

173

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Scalar-flat Kahler deformations: 12(g−1) moduli

174

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Scalar-flat Kahler deformations: 12(g−1) moduliLocally conformally flat def’ms: 30(g − 1) moduli

175

Example.

M = Σ× S2K = +1

K = −1Σ

S2

......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................

.....................

............................

............................................................

............................................................................................................................................................................................................................................................................

..................................

.................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

Scalar-flat Kahler deformations: 12(g−1) modulialmost-Kahler ASD deformat’ns: 30(g−1) moduli

176

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

Does this say anything about general ASD metrics?

Almost-Kahler ASD metrics sweep out an open setin the ASD moduli space.

177

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

Does this say anything about general ASD metrics?

Almost-Kahler ASD metrics sweep out an open setin the ASD moduli space.

Is this subset also closed?

178

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

Does this say anything about general ASD metrics?

Almost-Kahler ASD metrics sweep out an open setin the ASD moduli space.

Is this subset also closed?

Does one get entire connected components this way?

179

Last result indicates that almost-Kahler conditiongives extra control on ASD conformal geometry.

Inyoung Kim ’16: classification of almost-KahlerASD roughly the same as in scalar-flat Kahler case.

Does this say anything about general ASD metrics?

Almost-Kahler ASD metrics sweep out an open setin the ASD moduli space.

Is this subset also closed?

Does one get entire connected components this way?

Alas, No!

180

Theorem A.Consider 4-manifold M = Σ× S2,

181

Theorem A.Consider 4-manifold M = Σ× S2,

182

Theorem A.Consider 4-manifold M = Σ× S2,where Σ compact Riemann surface of genus g .

183

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

184

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

185

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

186

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

187

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

188

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

189

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

190

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

191

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

192

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

Same method simultaneously proves. . .

193

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,

194

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,

195

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

196

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

197

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

198

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

199

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

200

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

201

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

Proof hinges on a construction of hyperbolic 3-manifolds.

202

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

Proof hinges on a construction of hyperbolic 3-manifolds.

We begin by revisiting hyperbolic metrics on Σ.

203

H2.........................................................

..........................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................

....................................................

.......................

......

....................................................

.............................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

....................................................

.............................

.................................................................................

.................................................................................

.....................

...............................

.............................

.................................................................................

.................................................................................

.................................................................................

204

H2.........................................................

..........................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................

....................................................

.......................

......

....................................................

.............................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

....................................................

.............................

.................................................................................

.................................................................................

.....................

...............................

.............................

.................................................................................

.................................................................................

.................................................................................

.......................................

..............................................................................

.................................... ....................................

...................... .................................... .............................

.......

......................................................................................

...................... ..............

....................................

....................................

....................................

....................................................................

..................................

..................................

..................................

..................................

..................................

..................................

205

H2.........................................................

..........................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................

....................................................

.......................

......

....................................................

.............................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

....................................................

.............................

.................................................................................

.................................................................................

.....................

...............................

.............................

.................................................................................

.................................................................................

.................................................................................

.......................................

..............................................................................

.................................... ....................................

...................... .................................... .............................

.......

......................................................................................

...................... ..............

....................................

....................................

....................................

....................................................................

..................................

..................................

..................................

..................................

..................................

..................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

..............................................................................................................................

....

...............................................................................................................................

206

H2.........................................................

..........................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................

....................................................

.......................

......

....................................................

.............................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

....................................................

.............................

.................................................................................

.................................................................................

.....................

...............................

.............................

.................................................................................

.................................................................................

.................................................................................

.......................................

..............................................................................

.................................... ....................................

...................... .................................... .............................

.......

......................................................................................

...................... ..............

....................................

....................................

....................................

....................................................................

..................................

..................................

..................................

..................................

..................................

..................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

..............................................................................................................................

....

...............................................................................................................................

π1(Σ) ↪→ SO+(1, 2) = PSL(2,R)∩ ∩

SO+(1, 3) = PSL(2,C)

207

H2.........................................................

..........................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................

....................................................

.......................

......

....................................................

.............................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

.................................................................................

.......

.......

.......

............................................................

.................................................................................

....................................................

.............................

.................................................................................

.................................................................................

.....................

...............................

.............................

.................................................................................

.................................................................................

.................................................................................

.......................................

..............................................................................

.................................... ....................................

...................... .................................... .............................

.......

......................................................................................

...................... ..............

....................................

....................................

....................................

....................................................................

..................................

..................................

..................................

..................................

..................................

..................................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

..............................................................................................................................

....

...............................................................................................................................

π1(Σ) ↪→ SO+(1, 2) = PSL(2,R)∩ ∩

SO+(1, 3) = PSL(2,C)

208

........................................................

........................................

.................................

.............................

...........................

........................

.......................

......................

....................

....................

...................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

........................................

.........................................................

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

........

H3

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................................................................................

...........................................................

.............................................

....................................

..............................................................................................

......................................................................................................................................................

..........................................................................................................................................

................................................................................................................

..................................................

......................................................................................................................................................

.........................

..............................

............................

...................................................................................

...................................................................................

.......................................................

............................

.......................................................................

................................................................................

...............................................................

...............................................................................................................................................

.......................................

.....................

...........

................................................................................

......................................................................................................................................

.......................................

................................

...............................................................................................................................................

.......

.............................................

..........................

.......................... ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .............

..........................

209

........................................................

........................................

.................................

.............................

...........................

........................

.......................

......................

....................

....................

...................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

........................................

.........................................................

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

........

H3

Limit Set...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................................................................................

...........................................................

.............................................

....................................

..............................................................................................

......................................................................................................................................................

..........................................................................................................................................

................................................................................................................

..................................................

......................................................................................................................................................

.........................

..............................

............................

...................................................................................

...................................................................................

.......................................................

............................

.......................................................................

................................................................................

...............................................................

...............................................................................................................................................

.......................................

.....................

...........

................................................................................

......................................................................................................................................

.......................................

................................

...............................................................................................................................................

.......

.............................................

..........................

.......................... ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .............

..........................

210

........................................................

........................................

.................................

.............................

...........................

........................

.......................

......................

....................

....................

...................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

........................................

.........................................................

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

........

H3

Limit Set...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................................................................................

...........................................................

.............................................

....................................

..............................................................................................

......................................................................................................................................................

..........................................................................................................................................

................................................................................................................

..................................................

......................................................................................................................................................

.........................

..............................

............................

...................................................................................

...................................................................................

.......................................................

............................

.......................................................................

................................................................................

...............................................................

...............................................................................................................................................

.......................................

.....................

...........

................................................................................

......................................................................................................................................

.......................................

................................

...............................................................................................................................................

.......

.............................................

..........................

.......................... ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .............

..........................

π1(Σ)∼=−→ Γ ⊂ PSL(2,R) Fuchsian group

211

........................................................

........................................

.................................

.............................

...........................

........................

.......................

......................

....................

....................

...................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

........................................

.........................................................

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

........

H3

Limit Set...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................................................................................

...........................................................

.............................................

....................................

..............................................................................................

......................................................................................................................................................

..........................................................................................................................................

................................................................................................................

..................................................

......................................................................................................................................................

.........................

..............................

............................

...................................................................................

...................................................................................

.......................................................

............................

.......................................................................

................................................................................

...............................................................

...............................................................................................................................................

.......................................

.....................

...........

................................................................................

......................................................................................................................................

.......................................

................................

...............................................................................................................................................

.......

.............................................

..........................

.......................... ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .............

..........................

π1(Σ)∼=−→ Γ ⊂ PSL(2,C) Fuchsian group

212

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

......................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .........................

213

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

......................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .........................

Fuchsian quasi-Fuchsian

214

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

...................................................................................................................................................................................................... .......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

............................................... ...................................

...........................

...................................................................................................................................................

..........................................................................................................................................................

.............................................................................................................................................

..............................................................................

............................................................................................................

........................................

....................................................................

..........................................................................................

...............................

..........................................................................................................................................................................................................................................................

.............................................

..............................................................................

......................................................................................................

........................................

....................................................................

..........................................................................................

...............................

...................................................

....................................

.......................................................................................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ................... ......

....................

....................................................................... ................. ...

.....

...................................

... ................. ........................ ............... ...........

............... .......................... ................... .....

......... .............

............... ................ ....................................... ..................... ................ ...

...............

....................

Fuchsian quasi-Fuchsian

215

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

...................................................................................................................................................................................................... .......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

............................................... ...................................

...........................

...................................................................................................................................................

..........................................................................................................................................................

.............................................................................................................................................

..............................................................................

............................................................................................................

........................................

....................................................................

..........................................................................................

...............................

..........................................................................................................................................................................................................................................................

.............................................

..............................................................................

......................................................................................................

........................................

....................................................................

..........................................................................................

...............................

...................................................

....................................

.......................................................................................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ................... ......

....................

....................................................................... ................. ...

.....

...................................

... ................. ........................ ............... ...........

............... .......................... ................... .....

......... .............

............... ................ ....................................... ..................... ................ ...

...............

....................

Fuchsian quasi-Fuchsian

216

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

...................................................................................................................................................................................................... .......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

............................................... ...................................

...........................

...................................................................................................................................................

..........................................................................................................................................................

.............................................................................................................................................

..............................................................................

............................................................................................................

........................................

....................................................................

..........................................................................................

...............................

..........................................................................................................................................................................................................................................................

.............................................

..............................................................................

......................................................................................................

........................................

....................................................................

..........................................................................................

...............................

...................................................

....................................

.......................................................................................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ................... ......

....................

....................................................................... ................. ...

.....

...................................

... ................. ........................ ............... ...........

............... .......................... ................... .....

......... .............

............... ................ ....................................... ..................... ................ ...

...............

....................

Fuchsian quasi-Fuchsian

π1(Σ)∼=−→ Γ ⊂ PSL(2,C) quasi-Fuchsian group

217

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

...................................................................................................................................................................................................... .......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

............................................... ...................................

...........................

...................................................................................................................................................

..........................................................................................................................................................

.............................................................................................................................................

..............................................................................

............................................................................................................

........................................

....................................................................

..........................................................................................

...............................

..........................................................................................................................................................................................................................................................

.............................................

..............................................................................

......................................................................................................

........................................

....................................................................

..........................................................................................

...............................

...................................................

....................................

.......................................................................................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ................... ......

....................

....................................................................... ................. ...

.....

...................................

... ................. ........................ ............... ...........

............... .......................... ................... .....

......... .............

............... ................ ....................................... ..................... ................ ...

...............

....................

Fuchsian quasi-Fuchsian

π1(Σ)∼=−→ Γ ⊂ PSL(2,C) quasi-Fuchsian group

of Bers type

218

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

...................................................................................................................................................................................................... .......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

............................................... ...................................

...........................

...................................................................................................................................................

..........................................................................................................................................................

.............................................................................................................................................

..............................................................................

............................................................................................................

........................................

....................................................................

..........................................................................................

...............................

..........................................................................................................................................................................................................................................................

.............................................

..............................................................................

......................................................................................................

........................................

....................................................................

..........................................................................................

...............................

...................................................

....................................

.......................................................................................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ................... ......

....................

....................................................................... ................. ...

.....

...................................

... ................. ........................ ............... ...........

............... .......................... ................... .....

......... .............

............... ................ ....................................... ..................... ................ ...

...............

....................

Fuchsian quasi-Fuchsian

π1(Σ)∼=−→ Γ ⊂ PSL(2,C) quasi-Fuchsian group

of Bers type

Quasi-conformally conjugate to Fuchsian.

219

H3

........................................................

........................................

.................................

.............................

...........................

........................

.......................

......................

....................

....................

...................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

........................................

.........................................................

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

........

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................................................................................

...........................................................

.............................................

....................................

..............................................................................................

......................................................................................................................................................

..........................................................................................................................................

................................................................................................................

..................................................

......................................................................................................................................................

.........................

..............................

............................

...................................................................................

...................................................................................

.......................................................

............................

.......................................................................

................................................................................

...............................................................

...............................................................................................................................................

.......................................

.....................

...........

................................................................................

......................................................................................................................................

.......................................

................................

...............................................................................................................................................

.......

.............................................

..........................

.......................... ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. .............

..........................

220

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

221

X = H3/Γ

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

222

X = H3/Γ

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Γ Fuchsian

223

X = H3/Γ

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Γ Fuchsian

X ≈ Σ× R

224

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Γ quasi-Fuchsian

X ≈ Σ× R

225

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Γ quasi-Fuchsian

X ≈ Σ× R

Freedom: two points in Teichmuller space.

226

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Γ quasi-Fuchsian

X ≈ Σ× R

227

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Γ quasi-Fuchsian

X ≈ Σ× [0, 1]

228

s

s

1

0

f.......................................................................................................................................

...........................

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....

Γ quasi-Fuchsian

X ≈ Σ× [0, 1]

Tunnel-Vision function:

f : X → [0, 1]

229

s

s

1

0

f.......................................................................................................................................

...........................

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....

Γ quasi-Fuchsian

X ≈ Σ× [0, 1]

Tunnel-Vision function:

f : X → [0, 1]

∆f = 0

230

.......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

...................................................................................................................................................................................................... .......

.......

.......

.......

.......

.......

...................................................................................................................................................................................................................................................

.....................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................

..............................

.........................

.....................

....................

................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.......................................................................

.........................................

............................................... ...................................

...........................

...................................................................................................................................................

..........................................................................................................................................................

.............................................................................................................................................

..............................................................................

............................................................................................................

........................................

....................................................................

..........................................................................................

...............................

..........................................................................................................................................................................................................................................................

.............................................

..............................................................................

......................................................................................................

........................................

....................................................................

..........................................................................................

...............................

...................................................

....................................

.......................................................................................................................

................... .............

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ................... ......

....................

....................................................................... ................. ...

.....

...................................

... ................. ........................ ............... ...........

............... .......................... ................... .....

......... .............

............... ................ ....................................... ..................... ................ ...

...............

....................

Fuchsian quasi-Fuchsian

231

s

s

1

0

f.......................................................................................................................................

...........................

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....

Γ quasi-Fuchsian

X ≈ Σ× [0, 1]

Tunnel-Vision function:

f : X → [0, 1]

∆f = 0

232

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

233

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of conformally flat 4-manifolds:

234

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of conformally flat 4-manifolds:

M = [X × S1]/ ∼

235

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of conformally flat 4-manifolds:

M = [X × S1]/ ∼

∼: crush ∂X × S1 to ∂X .

236

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of conformally flat 4-manifolds:

M = [X × S1]/ ∼

237

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of conformally flat 4-manifolds:

M = [X × S1]/ ∼

g = f (1− f )[h + dt2]

238

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of conformally flat 4-manifolds:

M = [X × S1]/ ∼

g = f (1− f )[h + dt2]

239

X = H3/Γ

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Construction of conformally flat 4-manifolds:

M = [X × S1]/ ∼

g = f (1− f )[h + dt2]

Fuchsian case: Σ× S2 scalar-flat Kahler.

240

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

241

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

242

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

Choose k points p1, . . . , pk ∈ X

243

s

s

1

0

f.......................................................................................................................................

...........................

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....

Construction of ASD 4-manifolds:

Choose k points p1, . . . , pk ∈ X

satisfying∑kj=1 f (pj) ∈ Z.

244

s

s

1

0

f.......................................................................................................................................

...........................

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....

Construction of ASD 4-manifolds:

Choose k points p1, . . . , pk ∈ X

satisfying∑kj=1 f (pj) ∈ Z.

Can do if k 6= 1.

245

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

Let Gj be the Green’s function of pj:

246

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

Let Gj be the Green’s function of pj:

∆Gj = 2πδpj, Gj → 0 at ∂X

247

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

Let Gj be the Green’s function of pj, and set

V = 1 +

k∑j=1

Gj.

248

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

V = 1 +

k∑j=1

Gj.

249

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

V = 1 +

k∑j=1

Gj.

Choose P → (X−{p1, . . . , pk}) circle bundle withconnection form θ such that

dθ = ?dV .

250

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

V = 1 +

k∑j=1

Gj

dθ = ?dV

251

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

V = 1 +

k∑j=1

Gj

dθ = ?dV

252

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

M = P ∪ {p1, . . . , pk} ∪ ∂X

253

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

M = P ∪ {p1, . . . , pk} ∪ ∂X↓ ↓ ↓ ↓X = X − {p1, . . . , pk} ∪ {p1, . . . , pk} ∪ ∂X

254

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

M = P ∪ {p1, . . . , pk} ∪ ∂X

255

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

M = P ∪ {p1, . . . , pk} ∪ ∂X

≈(Σ× S2)#kCP2 scalar-flat Kahler

256

.......................................................................................................................

..........................

s s

Σ

X = Σ× [0, 1]

.......

.......

.......

.......

............................................................................................

.....................

.........................

.......................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................

..........................

......................

..........................................................................................................................................................................................

.............................

.................................................................................................................................................................................................................................................................

.......................................................................................................................................................

.................

..........................................................................................................................................................................................

.............................

.................................................................................................................................................................................................................................................................

.......................................................................................................................................................

.................

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

......................................................

...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..........................................................

......

..........................................................................................................................................................

.............................

....................................................................................

..........................................................................................................................................................

.............................

....................................................................................

................................................................................................................................

................................................................................................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

..............................................................................................................................

.............................................................................................................................................................................................................................................................................................................

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ....

............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ............. ....

...........................................................................................................................................................................................................

.......................................................................................................................................................................................................

..............................................................................................................................................................

.........................................................................................................................................................................

257

s ss

ssX = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

M = P ∪ {p1, . . . , pk} ∪ ∂X

≈(Σ× S2)#kCP2 scalar-flat Kahler

258

s ss

ssX = H3/Γ

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Construction of ASD 4-manifolds:

g = f (1− f )[V h + V −1θ2]

M = P ∪ {p1, . . . , pk} ∪ ∂X

Fuchsian case: (Σ× S2)#kCP2 scalar-flat Kahler

259

s

s

1

0

f.......................................................................................................................................

...........................

X = H3/Γ

....................................

....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................

.....................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.....................................................................................................................................................................................................................................................................................................................................................................................................

.................................................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................

................

................................................................................. .....................................................

......................................................................................................................................

.................................................................

.................................................................

.................................................................

.................................................................

................

................

.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

............

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....

Γ quasi-Fuchsian

X ≈ Σ× [0, 1]

Tunnel-Vision function:

f : X → [0, 1]

∆f = 0

260

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

261

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

262

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

263

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

264

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

265

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

266

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

267

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

268

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

Proof.

269

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

Proof.

b+[(Σ× S2)#kCP2] = 1.

270

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

Proof.

b+[(Σ× S2)#kCP2] = 1.

ω = df ∧ θ + V ? df .

271

Theorem.Let (M, [g]) be ASD manifold arisingfrom a quasi-Fuchsian 3-manifold (X, h) and aconfiguration of points in X.

Then ∃ almost-Kahler g ∈ [g] ⇐⇒ tunnel-visionfunction f : X → (0, 1) has no critical points.

Proof.

b+[(Σ× S2)#kCP2] = 1.

ω = df ∧ θ + V ? df .

272

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

273

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

274

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

275

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

276

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

277

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

278

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

279

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

280

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

281

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

282

Lemma.For any piecewise smooth Jordan curveγ ⊂ C and any ε > 0, there is a positive integerN such that, for every compact oriented surfaceΣ of genus g ≥ N , there is quasi-Fuchsian groupΓ ∼= π1(Σ) whose limit set Λ(Γ) ⊂ C ⊂ CP1 iswithin Hausdorff distance ε of γ.

If γ is invariant under ζ 7→ −ζ, and if g is even,we can also arrange for Λ(Γ) to also be invariantunder reflection through the origin.

Ahlfors-Bers: Quasi-conformal mappings

283

.......

.......

...................................................................................................................................

....................

.......................

............................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................

.......

.......

..........................................................................................................................................................................................................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

...............................

........................

.....................

.........................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

284

.......

.......

...................................................................................................................................

....................

.......................

............................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................

.......

.......

..........................................................................................................................................................................................................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

...............................

........................

.....................

.........................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.................................................................................

..................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

................................

................................................................................................

................................................................................................................................

................................................................................................................................

............................................................................................................

....................

...................................................................................................................

.............

................................................................................................................................

.......

.........................................................................................................................

.......

...............................

..........................................................................................

....................................................

...........................................................................

...............................................................................................................................

...............................................................................................................................

.............................................................

..................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

.................................

.................................

.....................................

...................................

............................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

......

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

.......

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

.............

.............

.............

.............

.............

.............

.............

.............

..

.............

.............

.............

.............

.............

.............

.............

.............

..

............. ............. ..........................

............................................................................................................................................................

.............

.............

.............

.............

..........................

...........................................................................................

..........................

..........................

..........................

...........................................................................................

..........................

.......................... ............. ............. ............. .

285

.......

.......

...................................................................................................................................

....................

.......................

............................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................

.......

.......

..........................................................................................................................................................................................................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

...............................

........................

.....................

.........................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.................................................................................

..................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

................................

................................................................................................

................................................................................................................................

................................................................................................................................

............................................................................................................

....................

...................................................................................................................

.............

................................................................................................................................

.......

.........................................................................................................................

.......

...............................

..........................................................................................

....................................................

...........................................................................

...............................................................................................................................

...............................................................................................................................

.............................................................

..................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

.................................

.................................

.....................................

...................................

............................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

......

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

.......

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

.............

.............

.............

.............

.............

.............

.............

.............

..

.............

.............

.............

.............

.............

.............

.............

.............

..

............. ............. ..........................

............................................................................................................................................................

.............

.............

.............

.............

..........................

...........................................................................................

..........................

..........................

..........................

...........................................................................................

..........................

.......................... ............. ............. ............. .

286

.......

.......

...................................................................................................................................

....................

.......................

............................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................

.......

.......

..........................................................................................................................................................................................................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

...............................

........................

.....................

.........................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.................................................................................

..................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

................................

................................................................................................

................................................................................................................................

................................................................................................................................

............................................................................................................

....................

...................................................................................................................

.............

................................................................................................................................

.......

.........................................................................................................................

.......

...............................

..........................................................................................

....................................................

...........................................................................

...............................................................................................................................

...............................................................................................................................

.............................................................

..................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

.................................

.................................

.....................................

...................................

............................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

......

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

.......

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

.............

.............

.............

.............

.............

.............

.............

.............

..

.............

.............

.............

.............

.............

.............

.............

.............

..

............. ............. ..........................

............................................................................................................................................................

.............

.............

.............

.............

..........................

...........................................................................................

..........................

..........................

..........................

...........................................................................................

..........................

.......................... ............. ............. ............. .

287

.......

.......

...................................................................................................................................

....................

.......................

............................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................

.......

.......

..........................................................................................................................................................................................................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

...............................

........................

.....................

.........................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.................................................................................

..................................

..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

....................

......................

.........................

..............................

............................................

.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

................................

................................................................................................

................................................................................................................................

................................................................................................................................

............................................................................................................

....................

...................................................................................................................

.............

................................................................................................................................

.......

.........................................................................................................................

.......

...............................

..........................................................................................

....................................................

...........................................................................

...............................................................................................................................

...............................................................................................................................

.............................................................

..................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

.................................

.................................

.....................................

...................................

............................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

......

..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

....................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

..................

.......

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

.................................................................................................................................................................................................................................................

.................................................................................................................................................................................................................................................

..................................

..................................

..................................

..................................

..................................

..................................

..................................

...

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

............. ............. ............. ............. ............. ............. ............. ............. ..

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................................................................................................

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

..........................

..........................

..........................

..........................

..

.............

.............

.............

.............

.............

.............

.............

.............

..

.............

.............

.............

.............

.............

.............

.............

.............

..

288

.......

.......

...................................................................................................................................

....................

.......................

............................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

.....................................................................................................................................................................................................................................

.......

.......

..........................................................................................................................................................................................................

..............................................

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

...............................

........................

.....................

.........................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

.........................................................................................................................................................................................................................................................................................................................

289

Theorem A.Consider 4-manifolds M = Σ× S2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], oflocally-conformally-flat classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

290

Theorem B. Fix an integer k ≥ 2, and thenconsider the 4-manifolds M = (Σ× S2)#kCP2,where Σ compact Riemann surface of genus g .

Then ∀ even g � 0, ∃ family [gt], t ∈ [0, 1], ofanti-self-dual conformal classes on M , such that

• ∃ scalar-flat Kahler metric g0 ∈ [g0]; but

• @ almost-Kahler metric g ∈ [g1].

291

Kia Ora!

292