On multifluid perturbations in scalar-tensor cosmology

Abstract

In this paper the scalar-tensor theory is applied to the study of perturbations in a multi-fluid universe, using the 1+3 covariant approach. Both scalar and harmonic decompositions are instituted on the perturbation equations. In particular, as an application, we study perturbations on a background FRW cosmology consisting of both radiation and dust in the presence of a scalar field. We consider both radiation-dominated and dust-dominated epochs, respectively, and study the results. During the analysis, quasi-static approximation is instituted. It is observed that the fluctuations of the energy density decrease with increasing redshift, for different values of $n$ of a power law $R^n$ model

Accepted for International Journal of Modern Physics D

References in corpus (6)

• Constraining f(R) Gravity as a Scalar Tensor Theory
• A Singularity Problem with f(R) Dark Energy
• On $f(R)$ gravity in scalar-tensor theories
• Gauge invariant perturbations of Scalar-Tensor Cosmologies: The vacuum case
• Breaking the cosmological background degeneracy by two-fluid perturbations in f(R) gravity
• A study of perturbations in scalar-tensor theory using 1+3 covariant approach