Spatially Homogeneous Bianchi Type-I Bulk Viscous Fluid Models in f(R, T) Gravity Theory

Abstract

We obtain some spatially homogeneous and anisotropic Bianchi type-I cosmological models in the presence of a bulk viscous fluid within the framework of f(R, T) gravity theory. Exact solutions of the field equations are presented by assuming that the anisotropy in the model is inversely proportional to some power of the average scale factor which leads to two types of cosmologies, one with power-law expansion and the other one with exponential expansion. The universe with power-law expansion has initial time singularity and approaches  to empty space for large time, whereas the universe with exponential expansion has singularity in the infinite past, which enters into the de Sitter phase at late time.  We also discuss the physical and dynamical features of the cosmological models.