The nonlinear power spectrum in clustering quintessence cosmologies

Abstract

We study the nonlinear evolution of density perturbations in cosmologies where the late-time accelerated expansion is driven by a quintessence field with vanishing speed of sound. For these models matter and quintessence perturbations are comoving and it is possible to write a single continuity equation for the total density fluctuations given by a weighted sum of the two components. Including the Euler equation for the common velocity field we solve the evolution equations for the nonlinear, total density power spectrum in the Time-Renormalization Group approach. In fact any cosmological observable is directly related by gravity only to the total density perturbations, with the two components being individually unobservable. We show that the clustering of quintessence perturbations induces small corrections with respect to the nonlinear evolution of power spectrum in smooth quintessence models described by the same equation of state. Such small corrections, however, contrast with the large effect of a vanishing speed of sound on the linear growth function at low redshift. For this reason, models with the same normalization of the linear density power spectrum can present significantly different nonlinear corrections depending on the value of the sound speed. Although such differences vanish in the w \rightarrow -1, ΛCDM limit, we argue that the relation between linear and nonlinear growth of structures should be properly taken into account in constraining models with inhomogeneous dark energy.

14 pages, 14 figures

References in corpus (17)

• Resumming Cosmological Perturbations via the Lagrangian Picture: One-loop Results in Real Space and in Redshift Space
• Nonlinear Evolution of Baryon Acoustic Oscillations
• The Effective Theory of Quintessence: the w<-1 Side Unveiled
• A critical look at cosmological perturbation theory techniques
• Flowing with Time: a New Approach to Nonlinear Cosmological Perturbations
• Multi-Point Propagators in Cosmological Gravitational Instability
• A Closure Theory for Non-linear Evolution of Cosmological Power Spectra
• Nonlinear Perturbation Theory Integrated with Nonlocal Bias, Redshift-space Distortions, and Primordial Non-Gaussianity
• Constraining dark energy with cross-correlated CMB and Large Scale Structure data
• Large-N expansions applied to gravitational clustering
• Fingerprinting dark energy
• Baryonic Acoustic Oscillations via the Renormalization Group
• Cosmological structure formation with clustering quintessence
• Can a galaxy redshift survey measure dark energy clustering?
• Multi-Point Propagators for Non-Gaussian Initial Conditions
• Fingerprinting Dark Energy II: weak lensing and galaxy clustering tests
• Constraining the Nature of Dark Energy using the SKA

Cited by in corpus (16)

• The Effective Field Theory of Dark Energy
• Effective Field Theory of Cosmological Perturbations
• Coarse-Grained Cosmological Perturbation Theory
• Structure formation with massive neutrinos: going beyond linear theory
• Nonlinear Power Spectrum from Resummed Perturbation Theory: a Leap Beyond the BAO Scale
• Non-linear Fields in Generalized Cosmologies
• An effective description of dark matter and dark energy in the mildly non-linear regime
• Limits on Clustering and Smooth Quintessence from the EFTofLSS
• Nonlinear cosmological consistency relations and effective matter stresses
• A short review on clustering dark energy
• Weak lensing probe of cubic Galileon model
• Nonlinear effects of dark energy clustering beyond the acoustic scales
• Probing dark energy using convergence power spectrum and bi-spectrum
• Clustering GCG: a viable option for unified dark matter-dark energy?
• Unified dark fluid with null sound speed as an alternative to phantom dark energy
• Nonlinear power spectrum in clustering and smooth dark energy models beyond the BAO scale