Confronting the sound speed of dark energy with future cluster surveys

Abstract

Future cluster surveys will observe galaxy clusters numbering in the hundred thousands. We consider this work how these surveys can be used to constrain dark energy parameters: in particular, the equation of state parameter w and the non-adiabatic sound speed c_s^2. We demonstrate that, in combination with Cosmic Microwave Background (CMB) observations from Planck, cluster surveys such as that in the ESA Euclid project will be able to determine a time-independent w with subpercent precision. Likewise, if the dark energy sound horizon falls within the length scales probed by the cluster survey, then c_s^2 can be pinned down to within an order of magnitude. In the course of this work, we also investigate the process of dark energy virialisation in the presence of an arbitrary sound speed. We find that dark energy clustering and virialisation can lead to dark energy contributing to the total cluster mass at approximately the 0.1% level at maximum.

24 pages, 7 figures, prepared for submission to JCAP

References in corpus (15)

• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• Probing dark energy perturbations: the dark energy equation of state and speed of sound as measured by WMAP
• Probing cosmological parameters with the CMB: Forecasts from full Monte Carlo simulations
• Cosmological structure formation in a homogeneous dark energy background
• Effects of the Sound Speed of Quintessence on the Microwave Background and Large Scale Structure
• Measuring Dark Energy Clustering with CMB-Galaxy Correlations
• Constraining the Evolution of Dark Energy with a Combination of Galaxy Cluster Observables
• Dark energy and the evolution of spherical overdensities
• Constraints on the sound speed of dark energy
• Can a galaxy redshift survey measure dark energy clustering?
• Virialization in Dark Energy Cosmology
• The signature of dark energy perturbations in galaxy cluster surveys
• Simulation studies of dark energy clustering induced by the formation of dark matter halos

Cited by in corpus (11)

• Structure formation in inhomogeneous Early Dark Energy models
• Full Investigation on the Dynamics of Power-Law Kinetic Quintessence
• Clustering dark energy and halo abundances
• A short review on clustering dark energy
• Constraints on dark energy from the Lyα forest baryon acoustic oscillations measurement of the redshift 2.3 Hubble parameter
• Dark energy perturbations in $N$-body simulations
• Dark energy homogeneity in general relativity: Are we applying it correctly?
• Spherical collapse of non-top-hat profiles in the presence of dark energy with arbitrary sound speed
• Effects of tidal gravitational fields in clustering dark energy models
• Tidal virialization of dark matter haloes with clustering dark energy
• On the virialization threshold for halo mass functions