Generation of Bianchi type V cosmological models with varying $\Lambda$-term

TL;DR

This paper develops Bianchi type V cosmological models with a time-varying cosmological constant, demonstrating their solvability for arbitrary scale functions and showing that the cosmological constant decreases over time, aligning with supernova observations.

Contribution

It introduces a generation technique to solve Einstein's equations for Bianchi type V models with a variable b3, expanding the class of solvable cosmological models.

Findings

The cosmological constant decreases over time.

Models are consistent with recent supernova data.

Solutions are obtained for specific cosmic scale functions.

Abstract

Bianchi type V perfect fluid cosmological models are investigated with cosmological term $\Lambda$ varying with time. 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 aspects of the models are also discussed.