The HORIZON Quintessential Simulations

The HORIZON Quintessential

Simulations

A. Füzfa1,2,

J.-M. Alimi2, V. Boucher3, F. Roy2

1Chargé de recherches F.N.R.S.,

University of Namur, Belgium

2LUTh – Observatoire de Paris

3Center for Particle Physics Phenomenology (CP3), University of Louvain, Belgium

Cosmological Constant

Fine-tuning and coincidence! Frozen DE : =ct for all time Homogeneous DE No direct interactions with matter

(purely gravitational)

What is the nature of Dark Energy (DE)? Quintessence

Dynamical DE : Qvaries with time

Inhomogeneous DE : k,t≠0 Possible direct interactions with

matter (not purely gravitational):

• DE-DM couplings (see PSC talk)

• DE-Baryons couplings

• Violation of the equivalence principle!

Casimir effect(Vacuum

Fluctuations)

Negative pressures!

Evacuum↑

Evacuum

Evacuum↑↑↑

Cosmic expansion produces more vacuum energy

Cosmic acceleration!

V

t

)(ta

Theoretical approaches to DE (quintessence, scalar-tensor gravity, …)

→ a(t),H(t), (t), G(t), D+(a) …

↓

Constraints from recent cosmic expansion

(Hubble diagrams of SNe Ia)→ m,Q

↓

Constraints from CMB angular fluctuations → b,CDM, 8lin

↓

Linear Matter Power Spectrum at z=0

and Linear growing modes D+(a)

→ initial conditions at zstart

↓

N-body simulations (CDM only, here) with corresponding H(a)

↓

Observational constraints :

weak-lensing, baryon acoustic oscillation, …

Dark energy and structure formation

Cosmological constant CDM

Quintessence scenari:

Ratra-Peebles potential (SUSY breaking, backreactions, …) RPCDM

Sugra potential (radiative correction of RPCDM at E~mPl) SUCDM

A) Considered theoretical models

2

3

4m

G

a

a

3 if 0 QQpa

QQm p

G

a

a3

3

4

VQ 2

² VpQ

2

²

4

V

²4exp4

GV

03

d

dV

a

a

Determination of m and ,Q) from SNLS 1st year data set

Degeneracies of the models (≈²=116 for 115 data) CDM vs QCDM’s : frozen vs dynamical DE RPCDM vs SUCDM: LSS tests of varying w(z)

B) Constraints from Hubble diagrams

SNe Iaredshift

range z<1.1

astart

CMB

Hubble Parameter Equation of State

Modification of CAMB code (in collaboration with V. Boucher, CP3): Cosmic expansion with quintessence (zeroth order) first order perturbations of the quintessence fluid (large-scales inhomogeneities) minimal-coupling

Results:

C) Constraints from CMB anisotropies

Angular Power Spectrum Linear Matter Power Spectrum

DE Clusterization

Different b/CDM

Different 8

D) Cosmological parameters table

Models/

ParametersCDM RPCDM SUCDM

m 0.24 0.2 0.18

b 0.042 0.041 0.042

8lin 0.74 0.58 0.45

/ =5 eV , =0.5 =3x106 GeV , =6

(SNLS data) 116.76 116.58 116.66

WMAP3)

(log-likelihood)

-486.25 -491.23 -502.35

H0=73 km/s/Mpc ; ,Q=1-m

astart=0.0403 ; ns=0.951

E) N-body quintessential simulations

Quintessence and cosmological constant DE models are almost equivalent to explain CMB and SNe Ia

LSS can settle the DE debate? New constraints on DE from LSS Criteria for detecting w(z) at z>>1 Predictions on LSS from alternatives to

Horizon Quintessential Simulations (CDM, RPCDM, SUCDM): L=500h-1Mpc ; Npart=Ncells=10243 ; CDM only (Particle-Mesh code) 65 snapshots (26+1) between as=0.04 and a0=1 3x1.6 Tb data 3 x 3000 h on Zahir (IDRIS) with 32 Procs, 3.7Gb RAM/Procs (300 time steps) Present storage: gaya.idris.fr => /fuzfa At disposal for the collaboration at horizon.obspm.fr:/storage

The results so far…

CDM@z=0

RPCDM@z=0

SUCDM@z=0

CDM@z=0

RPCDM@z=0

SUCDM@z=0

Tools developped: DarkCosmos (homogeneous cosmological models with quintessence ; adequacy

with Hubble diagrams of type Ia SNe and linear growing modes) CAMB+Q : CMB code with zero and first order behavior of quintessence Mpgrafic-Q : initial conditions from a CAMB generated power spectrum PM+Q : N-body DM only Particle-Mesh code with quintessence (normalization

and cosmic expansion)

Interesting analysis of quintessential simulations (HORIZON Collaboration): Effect of slope of power spectrum at large-scales (DE clusterization): 3D skeleton Baryon wiggles, correlation function (baryon acoustic oscillation) and non-linear

8

DM Clusters properties (mass function, velocity distribution, …) Semi-analytical approaches to populate with virtual objects Quintessential simulations for weak-lensing

Toward new constraints on DE from LSS?

Conclusions