Upload
kolja-kleineberg
View
824
Download
0
Tags:
Embed Size (px)
Citation preview
Kaj Kolja KLEINEBERG
Marián BOGUÑÁ
Universitat de Barcelona
@[email protected] in Kaj Kolja Kleineberg
Coexistence and domination
among interacting networks
Ecology 2.0:
Motivation Evolution Ecology 2.0 Summary & outlook
Topological evolution of large quasi-isolated onlinesocial network exhibits a dynamical percolation transition
Dynamical percolation transition demands new classof growing network models.
10
Motivation Evolution Ecology 2.0 Summary & outlook
Topological evolution of large quasi-isolated onlinesocial network exhibits a dynamical percolation transition
Dynamical percolation transition demands new classof growing network models.
10
Motivation Evolution Ecology 2.0 Summary & outlook
Online social network emerges on top of pre-existingunderlying social structure via viral and mass media influence
Online social network layer
Traditional contactnetwork layer
ActiveOnline & offline
PassiveOnline & offlineSusceptibleOnly offline
11
Motivation Evolution Ecology 2.0 Summary & outlook
Online social network emerges on top of pre-existingunderlying social structure via viral and mass media influence
Online social network layer
Traditional contactnetwork layer
ActiveOnline & offline
PassiveOnline & offlineSusceptibleOnly offline
Mass media activation Viral activation
Deactivation Viral reactivation
11
Motivation Evolution Ecology 2.0 Summary & outlook
Below a critical value of the viral parameterthe network becomes entirely passive
Λc
0.00 0.02 0.04 0.06 0.08
0.00
0.05
0.10
0.15
0.20
0.25
Λ
ΡA
Our model allows for the survival and death of onlinesocial networks.
12
Motivation Evolution Ecology 2.0 Summary & outlook
Below a critical value of the viral parameterthe network becomes entirely passive
Λc
0.00 0.02 0.04 0.06 0.08
0.00
0.05
0.10
0.15
0.20
0.25
Λ
ΡA
Our model allows for the survival and death of onlinesocial networks.
12
Motivation Evolution Ecology 2.0 Summary & outlook
Evolution of the digital society reveals balancebetween viral and mass media influence
Underlyingsocial structure
Balance betweenviral & mass media
influence
Survival and deathof networks
PRX 4, 031046, 2014
13
Motivation Evolution Ecology 2.0 Summary & outlook
Evolution of the digital society reveals balancebetween viral and mass media influence
Underlyingsocial structure
Balance betweenviral & mass media
influence
Survival and deathof networks
PRX 4, 031046, 2014
13
Motivation Evolution Ecology 2.0 Summary & outlook
Evolution of the digital society reveals balancebetween viral and mass media influence
Underlyingsocial structure
Balance betweenviral & mass media
influence
Survival and deathof networks
PRX 4, 031046, 2014
13
Motivation Evolution Ecology 2.0 Summary & outlook
Gause's law impedes the coexistence of species competingfor the same unique resource and is often violated in nature
Gause's lawspecies competingfor same resourcecannot coexist
Rich-get-richereven slightestadvantage isamplified
Naturecommunities
contain handful ofcoexisting species
15
Motivation Evolution Ecology 2.0 Summary & outlook
Gause's law impedes the coexistence of species competingfor the same unique resource and is often violated in nature
Gause's lawspecies competingfor same resourcecannot coexist
Rich-get-richereven slightestadvantage isamplified
Naturecommunities
contain handful ofcoexisting species
15
Motivation Evolution Ecology 2.0 Summary & outlook
Gause's law impedes the coexistence of species competingfor the same unique resource and is often violated in nature
Gause's lawspecies competingfor same resourcecannot coexist
Rich-get-richereven slightestadvantage isamplified
Naturecommunities
contain handful ofcoexisting species
15
Motivation Evolution Ecology 2.0 Summary & outlook
Digital ecosystem is formed by multiple networkscompeting for the attention of individuals
OSN 2
OSN 1
Underl.network
ActivePassiveSusceptible
Partial states}
Virality shareDistribution
between OSNsλi = ωi(ρ
a)λ
Rich-get-richermore active
networks obtainhigher share
Here: ωi = [ρai ]σ/
∑j [ρ
aj ]
σ
σ: activity affinity
Does rich-get-richer effect always lead to thedomination of a single network?
16
Motivation Evolution Ecology 2.0 Summary & outlook
Digital ecosystem is formed by multiple networkscompeting for the attention of individuals
OSN 2
OSN 1
Underl.network
ActivePassiveSusceptible
Partial states}
Virality shareDistribution
between OSNsλi = ωi(ρ
a)λ
Rich-get-richermore active
networks obtainhigher share
Here: ωi = [ρai ]σ/
∑j [ρ
aj ]
σ
σ: activity affinity
Does rich-get-richer effect always lead to thedomination of a single network?
16
Motivation Evolution Ecology 2.0 Summary & outlook
Digital ecosystem is formed by multiple networkscompeting for the attention of individuals
OSN 2
OSN 1
Underl.network
ActivePassiveSusceptible
Partial states}
Virality shareDistribution
between OSNsλi = ωi(ρ
a)λ
Rich-get-richermore active
networks obtainhigher share
Here: ωi = [ρai ]σ/
∑j [ρ
aj ]
σ
σ: activity affinity
Does rich-get-richer effect always lead to thedomination of a single network?
16
Motivation Evolution Ecology 2.0 Summary & outlook
Digital ecosystem is formed by multiple networkscompeting for the attention of individuals
OSN 2
OSN 1
Underl.network
ActivePassiveSusceptible
Partial states}
Virality shareDistribution
between OSNsλi = ωi(ρ
a)λ
Rich-get-richermore active
networks obtainhigher share
Here: ωi = [ρai ]σ/
∑j [ρ
aj ]
σ
σ: activity affinity
Does rich-get-richer effect always lead to thedomination of a single network?
16
Motivation Evolution Ecology 2.0 Summary & outlook
Digital ecosystem is formed by multiple networkscompeting for the attention of individuals
OSN 2
OSN 1
Underl.network
ActivePassiveSusceptible
Partial states}
Virality shareDistribution
between OSNsλi = ωi(ρ
a)λ
Rich-get-richermore active
networks obtainhigher share
Here: ωi = [ρai ]σ/
∑j [ρ
aj ]
σ
σ: activity affinity
Does rich-get-richer effect always lead to thedomination of a single network?
16
Motivation Evolution Ecology 2.0 Summary & outlook
Nonlinear dynamics of network evolution enablecoexistence despite rich-get-richer mechanism
Meanfield:
ρ̇ai = ρai
[λ ⟨k⟩ωi(ρ
a) [1− ρai ]− 1
]+
λ
νωi(ρ
a)ρsi
ρ̇si = −λ
νωi(ρ
a)ρsi
[1 + ν ⟨k⟩ ρai
]Coexistence solution: ρai = 1− 1
λ⟨k⟩ and ρsi = 0
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
17
Motivation Evolution Ecology 2.0 Summary & outlook
Nonlinear dynamics of network evolution enablecoexistence despite rich-get-richer mechanism
Meanfield:
ρ̇ai = ρai
[λ ⟨k⟩ωi(ρ
a) [1− ρai ]− 1
]+
λ
νωi(ρ
a)ρsi
ρ̇si = −λ
νωi(ρ
a)ρsi
[1 + ν ⟨k⟩ ρai
]Coexistence solution: ρai = 1− 1
λ⟨k⟩ and ρsi = 0
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
17
Motivation Evolution Ecology 2.0 Summary & outlook
Nonlinear dynamics of network evolution enablecoexistence despite rich-get-richer mechanism
Meanfield:
ρ̇ai = ρai
[λ ⟨k⟩ωi(ρ
a) [1− ρai ]− 1
]+
λ
νωi(ρ
a)ρsi
ρ̇si = −λ
νωi(ρ
a)ρsi
[1 + ν ⟨k⟩ ρai
]Coexistence solution: ρai = 1− 1
λ⟨k⟩ and ρsi = 0
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
17
Motivation Evolution Ecology 2.0 Summary & outlook
Nonlinear dynamics of network evolution enablecoexistence despite rich-get-richer mechanism
Meanfield:
ρ̇ai = ρai
[λ ⟨k⟩ωi(ρ
a) [1− ρai ]− 1
]+
λ
νωi(ρ
a)ρsi
ρ̇si = −λ
νωi(ρ
a)ρsi
[1 + ν ⟨k⟩ ρai
]Coexistence solution: ρai = 1− 1
λ⟨k⟩ and ρsi = 0
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
17
Motivation Evolution Ecology 2.0 Summary & outlook
Nonlinear dynamics of network evolution enablecoexistence despite rich-get-richer mechanism
Meanfield:
ρ̇ai = ρai
[λ ⟨k⟩ωi(ρ
a) [1− ρai ]− 1
]+
λ
νωi(ρ
a)ρsi
ρ̇si = −λ
νωi(ρ
a)ρsi
[1 + ν ⟨k⟩ ρai
]Coexistence solution: ρai = 1− 1
λ⟨k⟩ and ρsi = 0
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Coexistence σ=0.8
ρ1a
ρ2a
Unstable FPStable FP
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0Domination σ=1.2
ρ1a
ρ2a
StableUnstable
0.50 0.75 1.00 1.25 1.500.00
0.25
0.50
0.75
Bifurcation diagram
ρ1a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
17
Motivation Evolution Ecology 2.0 Summary & outlook
Maximum number of coexisting networksdepends on total virality and activity affinity
Overall attention to OSNs
Mor
e lik
ely
to e
ngag
ein
mor
e ac
tive
OS
Ns
Dom.2 coex.3 coex.4 coex.5 coex.
1 2 3 4 5 60.0
0.5
1.0
1.5
λ/λc1
σ
How many networks can coexist
Gause's law is violated as networks can coexistdespite rich-get-richer mechanism.
18
Motivation Evolution Ecology 2.0 Summary & outlook
Maximum number of coexisting networksdepends on total virality and activity affinity
Overall attention to OSNs
Mor
e lik
ely
to e
ngag
ein
mor
e ac
tive
OS
Ns
Dom.2 coex.3 coex.4 coex.5 coex.
1 2 3 4 5 60.0
0.5
1.0
1.5
λ/λc1
σ
How many networks can coexist
3 networks
2 networks
1 network
Stable configurations
Gause's law is violated as networks can coexistdespite rich-get-richer mechanism.
18
Motivation Evolution Ecology 2.0 Summary & outlook
Maximum number of coexisting networksdepends on total virality and activity affinity
Overall attention to OSNs
Mor
e lik
ely
to e
ngag
ein
mor
e ac
tive
OS
Ns
How many networks can coexist
1 2 3 4 5 6 7 8 9 100.0
0.5
1.0
1.5
λ/λc1
σ
Dom.2 coex.3 coex.4 coex.5 coex.
3 networks
2 networks
1 network
Stable configurations
Gause's law is violated as networks can coexistdespite rich-get-richer mechanism.
18
Motivation Evolution Ecology 2.0 Summary & outlook
Maximum number of coexisting networksdepends on total virality and activity affinity
Overall attention to OSNs
Mor
e lik
ely
to e
ngag
ein
mor
e ac
tive
OS
Ns
How many networks can coexist
1 2 3 4 5 6 7 8 9 100.0
0.5
1.0
1.5
λ/λc1
σ
Dom.2 coex.3 coex.4 coex.5 coex.
3 networks
2 networks
1 network
Stable configurations
Gause's law is violated as networks can coexistdespite rich-get-richer mechanism.
18
Motivation Evolution Ecology 2.0 Summary & outlook
Noise and the shape of the basin of attractionlimit observed digital diversity
Multi stabilityseveral stablefixed points
Noisein full dynamical
model
Dom.Coex.
2 4 6 8 100.0
0.4
0.8
1.2
λ/λc1
σ
Reachability for 2 networks
→ Effective critical lines for more networks saturate atsuccessively lower values σi,eff
c
Evenwithout precise knowledge of the empiricalparameters our theory explainsmoderate diversity.
19
Motivation Evolution Ecology 2.0 Summary & outlook
Noise and the shape of the basin of attractionlimit observed digital diversity
Multi stabilityseveral stablefixed points
Noisein full dynamical
model
Dom.Coex.
2 4 6 8 100.0
0.4
0.8
1.2
λ/λc1
σ
Reachability for 2 networks
→ Effective critical lines for more networks saturate atsuccessively lower values σi,eff
c
Evenwithout precise knowledge of the empiricalparameters our theory explainsmoderate diversity.
19
Motivation Evolution Ecology 2.0 Summary & outlook
Noise and the shape of the basin of attractionlimit observed digital diversity
Multi stabilityseveral stablefixed points
Noisein full dynamical
model
Dom.Coex.
2 4 6 8 100.0
0.4
0.8
1.2
λ/λc1
σ
Reachability for 2 networks
→ Effective critical lines for more networks saturate atsuccessively lower values σi,eff
c
Evenwithout precise knowledge of the empiricalparameters our theory explainsmoderate diversity.
19
Motivation Evolution Ecology 2.0 Summary & outlook
Reachability of the coexistence solutiondepends on the influence of mass media
Reachabilityprobability to
coexist
Mass mediainfluences thereachability 0 4 8 12
0.0
0.2
0.4
0.6
0.8
1.0
ν
Probability coex.
Recall: µi = λi/ν, small ν means high media influence
The influence ofmass media enhances the observeddigital diversity.
20
Motivation Evolution Ecology 2.0 Summary & outlook
Reachability of the coexistence solutiondepends on the influence of mass media
Reachabilityprobability to
coexist
Mass mediainfluences thereachability 0 4 8 12
0.0
0.2
0.4
0.6
0.8
1.0
ν
Probability coex.
Recall: µi = λi/ν, small ν means high media influence
The influence ofmass media enhances the observeddigital diversity.
20
Motivation Evolution Ecology 2.0 Summary & outlook
Ecological theory of the digital world explains whywe observe a moderate number of coexisting networks
Coexistencedespite rich-get-richer
Damageto diversity is irreversible
Moderatedigital diversity observed
Media effectscontrols observed diversity
Sci. Rep. 5, 10268, 2015
21
Motivation Evolution Ecology 2.0 Summary & outlook
Ecological theory of the digital world explains whywe observe a moderate number of coexisting networks
Coexistencedespite rich-get-richer
Damageto diversity is irreversible
Moderatedigital diversity observed
Media effectscontrols observed diversity
Sci. Rep. 5, 10268, 2015
21
Motivation Evolution Ecology 2.0 Summary & outlook
Ecological theory of the digital world explains whywe observe a moderate number of coexisting networks
Coexistencedespite rich-get-richer
Damageto diversity is irreversible
Moderatedigital diversity observed
Media effectscontrols observed diversity
Sci. Rep. 5, 10268, 2015
21
Motivation Evolution Ecology 2.0 Summary & outlook
Ecological theory of the digital world explains whywe observe a moderate number of coexisting networks
Coexistencedespite rich-get-richer
Damageto diversity is irreversible
Moderatedigital diversity observed
Media effectscontrols observed diversity
Sci. Rep. 5, 10268, 2015
21
Motivation Evolution Ecology 2.0 Summary & outlook
Multiscale theory of the digital world: From individual tiesto globally interacting networks
Individuals Interacting Worldwide
Mod
el Strength ofsocial ties
Res
ult Weak ties
have highertransmissibility
Viral + mediaeffect & under-lying structure
Viral effect is about fourtimes stronger
Rich-get-richer& diminishingreturns
Coexistance of amoderate numberof services
Network of net-works & effectiveactivity
Local networks canprevail under certainconditions
Focu
s
12
3
101 - 102 105 - 106 106 - 109 >109
Ord
er
Isolatednetwork networks
PRX 4, 031046 Sci. Rep. 5, 10268 arxiv:1504.01368 23
Motivation Evolution Ecology 2.0 Summary & outlook
Multiscale theory of the digital world: From individual tiesto globally interacting networks
Individuals Interacting Worldwide
Mod
el Strength ofsocial ties
Res
ult Weak ties
have highertransmissibility
Viral + mediaeffect & under-lying structure
Viral effect is about fourtimes stronger
Rich-get-richer& diminishingreturns
Coexistance of amoderate numberof services
Network of net-works & effectiveactivity
Local networks canprevail under certainconditions
Focu
s
12
3
101 - 102 105 - 106 106 - 109 >109
Ord
er
Isolatednetwork networks
PRX 4, 031046 Sci. Rep. 5, 10268 arxiv:1504.01368 23
Motivation Evolution Ecology 2.0 Summary & outlook
Multiscale theory of the digital world: From individual tiesto globally interacting networks
Individuals Interacting Worldwide
Mod
el Strength ofsocial ties
Res
ult Weak ties
have highertransmissibility
Viral + mediaeffect & under-lying structure
Viral effect is about fourtimes stronger
Rich-get-richer& diminishingreturns
Coexistance of amoderate numberof services
Network of net-works & effectiveactivity
Local networks canprevail under certainconditions
Focu
s
12
3
101 - 102 105 - 106 106 - 109 >109
Ord
er
Isolatednetwork networks
PRX 4, 031046 Sci. Rep. 5, 10268 arxiv:1504.01368 23
Motivation Evolution Ecology 2.0 Summary & outlook
Multiscale theory of the digital world: From individual tiesto globally interacting networks
Individuals Interacting Worldwide
Mod
el Strength ofsocial ties
Res
ult Weak ties
have highertransmissibility
Viral + mediaeffect & under-lying structure
Viral effect is about fourtimes stronger
Rich-get-richer& diminishingreturns
Coexistance of amoderate numberof services
Network of net-works & effectiveactivity
Local networks canprevail under certainconditions
Focu
s
12
3
101 - 102 105 - 106 106 - 109 >109
Ord
er
Isolatednetwork networks
PRX 4, 031046 Sci. Rep. 5, 10268 arxiv:1504.01368 23
Just as a monopoly in economy is a threat to free markets, the lack of
poses a threat to the digital diversity
freedom of information.
Motivation Evolution Ecology 2.0 Summary & outlook
Digital diversity is important. So write downthe references and contact information now!
References:
K.-K. Kleineberg, M. Boguña.PRX 4, 031046, 2014
K.-K. Kleineberg, M. Boguña.Sci. Rep. 5, 10268, 2015
K.-K. Kleineberg, M. Boguña.arxiv:1504.01368, 2015
Kaj Kolja Kleineberg:
• @KoljaKleineberg
in • Kaj Kolja Kleineberg25
Motivation Evolution Ecology 2.0 Summary & outlook
Digital diversity is important. So write downthe references and contact information now!
References:
K.-K. Kleineberg, M. Boguña.PRX 4, 031046, 2014
K.-K. Kleineberg, M. Boguña.Sci. Rep. 5, 10268, 2015
K.-K. Kleineberg, M. Boguña.arxiv:1504.01368, 2015
Kaj Kolja Kleineberg:
• @KoljaKleineberg← Slides!
in • Kaj Kolja Kleineberg25
Motivation Evolution Ecology 2.0 Summary & outlook
CREDITS
Vintage globe: jayneanddObsolete hardware David Haywardoil field: Damian GadalCat attention: David CornejoCables: jerry johnNetwork "ring": Adam BeasleyBoxing gloves: Gabriele FumeroWorld: Lorenzo BaldiniMegaphone: Alex Auda SamoraBiohazard: Shailendra ChouhanLayer icon: MentaltoyBalance (scale) icon: Roman KovbasyukDeath symbol: Mila RedkoPie Chart: P.J. Onori
Money sack: Lemon LiuTeam icon: Joshua JonesHand icon: irene hoffmanarm with muscle: Sergey KrivoyTime: Richard de VosNo: P.J. OnoriLocal: Phil GoodwinSummary (article) icon: Stefan Parnarovflower: Nishanth JoisRead magazine: Evan TravelsteadGlobe 2: Ealancheliyan s3 arrows: Juan Pablo Bravodices: Drew Ellis
Icons: thenounproject.com
Kaj Kolja Kleineberg:
• @KoljaKleineberg
in • Kaj Kolja Kleineberg26