Some FRW Models of Accelerating Universe with Dark Energy

TL;DR

This paper explores specific FRW cosmological models with dark energy, using Berman's law to derive solutions with constant deceleration, and finds dark energy dominates the current universe, aligning with observations.

Contribution

It introduces exact solutions for FRW models with interacting dark energy and perfect fluid using Berman's law, highlighting dark energy's dominance in the current universe.

Findings

Dark energy dominates the current universe

Models with constant deceleration parameter are derived

Results align with observational data

Abstract

The paper deals with a spatially homogeneous and isotropic FRW space-time filled with perfect fluid and dark energy components. The two sources are assumed to interact minimally, and therefore their energy momentum tensors are conserved separately. A special law of variation for the Hubble parameter proposed by Berman (1983) has been utilized to solve the field equations. The Berman's law yields two explicit forms of the scale factor governing the FRW space-time and constant values of deceleration parameter. The role of dark energy with variable equation of state parameter has been studied in detail in the evolution of FRW universe. It has been found that dark energy dominates the universe at the present epoch, which is consistent with the observations. The physical behavior of the universe is discussed in detail.