Matter power spectrum for the generalized Chaplygin gas model: The relativistic case

Abstract

The generalized Chaplygin gas (GCG) model is the prototype of a unified model of dark energy (DE) and dark matter (DM). It is characterized by equation-of-state (EoS) parameters $A$ and $\alpha$. We use a statistical analysis of the 2dFGRS data to constrain these parameters. In particular, we find that very small (close to zero) and very large values ($\alpha \gg 1$) of the equation-of-state parameter $\alpha$ are preferred. To test the validity of this type of unification of the dark sector we admit the existence of a separate DM component in addition to the Chaplygin gas and calculate the probability distribution for the fractional contributions of both components to the total energy density. This analysis favors a model for which the Universe is nearly entirely made up of the separate DM component with an almost negligible Chaplygin gas part. This confirms the results of a previous Newtonian analysis.

Latex file, 8 pages, 15 figures in eps format

References in corpus (3)

• Bulk Viscous Cosmology
• Gauge-invariant analysis of perturbations in Chaplygin gas unified models of dark matter and dark energy
• Dissipative or Conservative cosmology with dark energy ?

Cited by in corpus (5)

• Nonlinear Chaplygin Gas Cosmologies
• Ruling out the Modified Chaplygin Gas Cosmologies
• Generalized models of unification of dark matter and dark energy
• Thermodynamics of Modified Chaplygin-Jacobi Gas and Modified Chaplygin-Abel Gas: Stability Analysis and Observational Constraints
• Scalar and vector perturbations in a universe with nonlinear perfect fluid