Cosmic dynamics and qualitative study of Rastall model with spatial curvature

Abstract

We investigate the cosmic dynamics of Rastall gravity in non-flat Friedmann-Robertson-Walker (FRW) space-time with barotropic fluid. In this context, we are concerned about the class of model satisfying the affine equation of state. We derive the autonomous system for the Rastall model with barotropic fluid. We apply the derived system to investigate the critical points for expanding and bouncing cosmologies and their stable nature and cosmological properties. The expanding cosmology yields de Sitter universe at late times with decelerating past having matter and radiation dominated phases. Investigation of autonomous system for bouncing cosmology yields oscillating solutions in positive spatial curvature region. We also investigate the consequences of setting-up a model of non-singular universe by using energy conditions. The distinct features of the Rastall model compared to the standard model have been discussed in detail.

Dynamics of a Cosmological Model in f(R,T) Gravity: I. On Invariant Planes

“…Dynamical system analysis is a powerful mathematical tool for studying the dynamical behavior of models of the universe without analytically solving field equations. This method has been used for a broad class of models in different gravity theories [47][48][49][50]. Equilibrium points in the governing equations of cosmological models can describe different epochs of the universe.…”