LRS Bianchi I model with perfect fluid equation of state

TL;DR

This paper derives and analyzes solutions for LRS Bianchi-I cosmological models with various perfect fluid equations of state, highlighting models that exhibit deceleration and acceleration phases.

Contribution

It provides a unified systematic approach to solutions in LRS Bianchi-I spacetime with perfect fluids, including some new solutions and detailed analysis of different fluid models.

Findings

Vacuum energy model shows transition from deceleration to acceleration.

Dust, stiff matter, and radiation models only describe decelerated expansion.

Several new solutions to the field equations are presented.

Abstract

The general solution of the field equations in LRS Bianchi-I space-time with perfect fluid equation-of-state (EoS) is presented. The models filled with dust, vacuum energy, Zel'dovich matter and disordered radiation are studied in detail. A unified and systematic treatment of the solutions is presented, and some new solutions are found. The dust, stiff matter and disordered radiation models describe only a decelerated universe, whereas the vacuum energy model exhibits a transition from a decelerated to an accelerated phase.