Clarifying spherical collapse in coupled dark energy cosmologies

Abstract

The spherical collapse model is often used to follow the evolution of overdensities into the nonlinear regime. We describe the correct approach to be used in coupled dark energy cosmologies, where a fifth force, different from gravity and mediated by the dark energy scalar field, influences the collapse. We reformulate the spherical collapse description by deriving it directly from the set of nonlinear hydrodynamical Navier Stokes equations. By comparing with the corresponding relativistic equations, we show how the fifth force should be taken into account within the spherical collapse picture and clarify the problems arising when an inhomogeneous scalar field is considered within a spherical collapse picture. We then apply our method to the case of coupled quintessence, where the fifth force acts among cold dark matter particles, and to growing neutrino quintessence, where the fifth force acts between neutrinos. Furthermore, we review this method when applied to standard cosmologies and apply our analysis to minimally coupled quintessence and check past results for early dark energy parametrizations.

16 pages, 13 figures, published in Physical Review D, minor changes and corrections

References in corpus (18)

• Dynamics of dark energy with a coupling to dark matter
• Interacting Dark Energy and Dark Matter: observational Constraints from Cosmological Parameters
• Flowing with Time: a New Approach to Nonlinear Cosmological Perturbations
• Coupled and Extended Quintessence: theoretical differences and structure formation
• Growing Matter
• Dark Interactions and Cosmological Fine-Tuning
• Constraining Interactions in Cosmology's Dark Sector
• Growing neutrinos and cosmological selection
• Structure formation in the presence of dark energy perturbations
• Neutrino Dark Energy -- Revisiting the Stability Issue
• Neutrino clustering in growing neutrino quintessence
• Impact of three years of data from the Wilkinson Microwave Anisotropy Probe on cosmological models with dynamical dark energy
• Mass functions in coupled Dark Energy models
• Do WMAP data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?
• Voids of dark energy
• Cluster abundances and S-Z power spectra: effects of non-Gaussianity and early dark energy
• Speed of Sound in the Mass Varying Neutrinos Scenario
• Neutrino Lumps in Quintessence Cosmology

Cited by in corpus (3)

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