Nonlinear viscous cosmological models in f(R,T) gravity

Abstract

This article presents nonlinear viscous cosmological model of the universe that arises in the modified gravity theory in which the Lagrangian of the gravitational action contains a general function [Formula: see text], where [Formula: see text] and [Formula: see text] denote the curvature scalar and the trace of the energy–momentum tensor, respectively, in the flat Friedmann-Robertson-Walker background metric with isotropic fluid. We obtain cosmological solutions in [Formula: see text] theory of gravity, specially for the choice [Formula: see text] with nonlinear viscosity described by nonlinear Israel Stewart theory. The physical and geometrical properties of the models in [Formula: see text] gravity, where [Formula: see text] and [Formula: see text] are coupling parameters, with nonlinear Israel Stewart theory are studied in detail. The analysis of the variation of bulk viscous pressure, energy density, scale factor, Hubble parameter and deceleration parameter with cosmic evolution is done in the nonlinear Israel Stewart theory with [Formula: see text] gravity. The stability analysis of the equilibrium points of the dynamical system associated with the exponential evolution of the universe in [Formula: see text] gravity theory with nonlinear dissipative effects is also studied.