The HORIZON Quintessential Simulations A.Füzfa 1,2, J.-M. Alimi 2, V. Boucher 3, F. Roy 2 1 Chargé de recherches F.N.R.S., University of Namur, Belgium 2 LUTh – Observatoire de Paris 3 Center 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 : Q varies 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! E vacuum ↑ E vacuum E vacuum ↑↑↑ Cosmic expansion produces more vacuum energy Cosmic acceleration!
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, 8 lin ↓ Linear Matter Power Spectrum at z=0 and Linear growing modes D + (a) → initial conditions at z start ↓ 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~m Pl ) SUCDM A) Considered theoretical models
Determination of m and ,Q) from SNLS 1 st 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 Ia redshift range z<1.1 a start CMB Hubble Parameter Equation of State
Modification of CAMB code (in collaboration with V. Boucher, CP3): Cosmic expansion with quintessence (zero th order) first order perturbations of the quintessence fluid (large-scales inhomogeneities) minimal-coupling Results: C) Constraints from CMB anisotropies Angular Power SpectrumLinear Matter Power Spectrum DE Clusterization Different b / CDM Different 8
D) Cosmological parameters table Models / Parameters CDM RPCDMSUCDM mm bb 8 lin / =5 eV, =0.5 =3x10 6 GeV, =6 (SNLS data) WMAP3) (log-likelihood) H 0 =73 km/s/Mpc ; ,Q =1- m a start = ; n s =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 -1 Mpc ; N part =N cells = ; CDM only (Particle-Mesh code) 65 snapshots (2 6 +1) between a s =0.04 and a 0 =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…
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