Role of the constant deceleration parameter in cosmological models with perfect fluid and dark energy

TL;DR

This paper explores Bianchi type I cosmological models with perfect fluid and dark energy, assuming a constant deceleration parameter, and derives two models with distinct physical behaviors.

Contribution

It introduces two new cosmological models with constant deceleration parameters using Berman's law, considering separate conservation of perfect fluid and dark energy.

Findings

Two distinct cosmological models with different deceleration parameters.

Physical analysis of models' behaviors over cosmic evolution.

Insights into the role of constant deceleration in anisotropic universes.

Abstract

The main purpose of the present paper is to investigate LRS Bianchi type I metric in the presence of perfect fluid and dark energy. In order to obtain a deterministic solution of the field equations we have assumed that, the two sources of the perfect fluid and dark energy interact minimally with separate conservation of their energy momentum tensors. The EoS parameter of the perfect fluid is also assumed to be constant. In addition to these we have used a special law of variation of Hubble parameter proposed by Berman that yields constant deceleration parameter. For two different values of the constant deceleration parameters we have obtained two different cosmological models. The physical behaviors of both the models have been discussed by using some physical parameters.