A cosmological model with time dependent $\Lambda$, $G$ and viscous fluid in General Relativity

Abstract

In this paper, we investigate Bianchi type$-V$ cosmological models with bulk viscous fluid and time varying cosmological $\Lambda$ and Newtonian $G$ parameters. The Einstein's field equations have been transformed into a coupling non-linear, first-order differential equations, and the fourth-order Runge-Kutta method of numerical integration has been used to integrate the differential equations with appropriate initial conditions consistent with current cosmological observations. We show that the model describes a universe that starts off with a negative cosmological term, as well as a matter-dominated and decelerated early epoch that, eventually becomes $\Lambda$-dominated and expanding with acceleration, in concordance with current observations.

Accepted for Publication in Frontiers in Astrophysics and Space Science, 13 pages, 6 figures