Generation of Bianchi Type V Bulk Viscous Cosmological Models with Time Dependent $\Lambda$-Term

TL;DR

This paper develops Bianchi type V bulk viscous cosmological models with a time-dependent cosmological constant, showing solutions for arbitrary scale functions and a decreasing Lambda consistent with supernova observations.

Contribution

It introduces a generation technique to solve Einstein's equations for Bianchi type V models with variable Lambda and viscous fluids, expanding the class of solvable cosmological models.

Findings

Cosmological constant decreases over time.

Models are consistent with supernova observations.

Solutions are obtained for arbitrary cosmic scale functions.

Abstract

Bianchi type V bulk viscous fluid cosmological models are investigated with dynamic cosmological term $\Lambda(t)$. Using a generation technique (Camci {\it et al.}, 2001), it is shown that the Einstein's field equations are solvable for any arbitrary cosmic scale function. Solutions for particular forms of cosmic scale functions are also obtained. The cosmological constant is found to be decreasing function of time, which is supported by results from recent type Ia supernovae observations. Some physical and geometrical aspects of the models are also discussed.