Bianchi Type V Viscous Fluid Cosmological Models in Presence of Decaying Vacuum Energy

TL;DR

This paper develops a Bianchi type V cosmological model with viscous fluid and a decaying vacuum energy, showing how it evolves from deceleration to acceleration and isotropizes over time.

Contribution

It introduces a new anisotropic cosmological model incorporating shear viscosity and a variable cosmological term, analyzing its evolution and isotropization.

Findings

Model exhibits initial decelerating expansion transitioning to acceleration.

Shear viscosity accelerates the isotropization process.

Universe approaches isotropy asymptotically.

Abstract

Bianchi type V viscous fluid cosmological model for barotropic fluid distribution with varying cosmological term $\Lambda$ is investigated. We have examined a cosmological scenario proposing a variation law for Hubble parameter $H$ in the background of homogeneous, anisotropic Bianchi type V space-time. The model isotropizes asymptotically and the presence of shear viscosity accelerates the isotropization. The model describes a unified expansion history of the universe indicating initial decelerating expansion and late time accelerating phase. Cosmological consequences of the model are also discussed.