Entropic cosmology in a dissipative universe

Abstract

The bulk viscosity of cosmological fluid and the creation of cold dark matter both result in the generation of irreversible entropy (related to dissipative processes) in a homogeneous and isotropic universe. To consider such effects, the general cosmological equations are reformulated, focusing on a spatially flat matter-dominated universe. A phenomenological entropic-force model is examined that includes constant terms as a function of the dissipation rate ranging from $\tilde{\mu }=0$, corresponding to a nondissipative $\Lambda$CDM (lambda cold dark matter) model, to $\tilde{\mu }=1$, corresponding to a fully-dissipative CCDM (creation of cold dark matter) model. A time evolution equation is derived for the matter density contrast, in order to characterize density perturbations in the present entropic-force model. It is found that the dissipation rate affects the density perturbations even if the background evolution of the late universe is equivalent to that of a fine-tuned pure $\Lambda$CDM model. With increasing dissipation rate $\tilde{\mu }$, the calculated growth rate for the clustering gradually deviates from observations, especially at low redshifts. However, the growth rate for low $\tilde{\mu }$ (less than 0.1) is found to agree well with measurements. A low-dissipation model predicts a smaller growth rate than does the pure $\Lambda$CDM model (for which $\tilde{\mu }=0$). More detailed data are needed to distinguish the low-dissipation model from the pure $\Lambda$CDM one.

Final version accepted for publication in PRD. References are corrected. [14 pages, 7 figures]

References in corpus (32)

• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Cosmological Constraints from the SDSS Luminous Red Galaxies
• A test of the nature of cosmic acceleration using galaxy redshift distortions
• Large-scale instability in interacting dark energy and dark matter fluids
• Interacting holographic dark energy model in non-flat universe
• The new form of the equation of state for dark energy fluid and accelerating universe
• Cosmologies with Energy Exchange
• The 2dF-SDSS LRG and QSO Survey: QSO clustering and the L-z degeneracy
• Entropic Accelerating Universe
• The 2dF-SDSS LRG and QSO Survey: The LRG 2-Point Correlation Function and Redshift-Space Distortions
• Does Bulk Viscosity Create a Viable Unified Dark Matter Model?
• Bulk Viscous Cosmology
• Thermodynamical description of the interaction between holographic dark energy and dark matter
• Hubble expansion and structure formation in the "running FLRW model" of the cosmic evolution
• Can a matter-dominated model with constant bulk viscosity drive the accelerated expansion of the universe?
• Matter creation and cosmic acceleration
• Exploring a matter-dominated model with bulk viscosity to drive the accelerated expansion of the Universe
• Friedmann cosmology with bulk viscosity: a concrete model for dark energy
• Inflation in Entropic Cosmology: Primordial Perturbations and non-Gaussianities
• Entropy evolution of universes with initial and final de Sitter eras
• Gravitationally Induced Particle Production: Thermodynamics and Kinetic Theory
• Non-adiabatic dark fluid cosmology
• Confronting Dark Energy Models using Galaxy Cluster Number Counts
• Post-$Planck$ constraints on interacting vacuum energy
• Cardy-Verlinde formula in FRW Universe with inhomogeneous generalized fluid and dynamical entropy bounds near the future singularity
• Non-adiabatic-like accelerated expansion of the late universe in entropic cosmology
• Constraining Entropic Cosmology
• Vacuum energy and cosmological evolution
• Effective growth of matter density fluctuations in the running LCDM and LXCDM models
• CCDM model from quantum particle creation: constraints on dark matter mass
• CMB acoustic scale in the entropic-like accelerating universe

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• Horizon thermodynamics in holographic cosmological models with a power-law term
• Entropy production due to adiabatic particle creation in a holographic dissipative cosmology
• Evolution of dissipative and non-dissipative universes in holographic cosmological models with a power-law term