Is the cosmological dark sector better modeled by a generalized Chaplygin gas or by a scalar field?

Abstract

Both scalar fields and (generalized) Chaplygin gases have been widely used separately to characterize the dark sector of the Universe. Here we investigate the cosmological background dynamics for a mixture of both these components and quantify the fractional abundances that are admitted by observational data from supernovae of type Ia and from the evolution of the Hubble rate. Moreover, we study how the growth rate of (baryonic) matter perturbations is affected by the dark-sector perturbations.

20 pages, 9 figures, substantially revised, section on matter perturbations added, accepted for publication in EPJC

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Cited by in corpus (1)

• Homogeneous Cosmological Models in Weyl's Geometrical Scalar-Tensor Theory