Accelerating Bianchi Type-V Cosmology with Perfect Fluid and Heat Flow in Saez-Ballester Theory

TL;DR

This paper presents new cosmological models within Saez-Ballester theory that feature a time-varying deceleration parameter, successfully describing the universe's transition from deceleration to acceleration in line with observations.

Contribution

It introduces a novel scale factor form leading to a dynamic deceleration parameter in Saez-Ballester theory, aligning theoretical models with recent cosmological data.

Findings

The model's current deceleration parameter matches observed values (-0.67).

The scale factor form describes universe's transition from deceleration to acceleration.

Physical and geometric properties of the models are consistent with observations.

Abstract

In this paper we discuss the law of variation of scale factor $a = (t^{k}e^{t})^{\frac{1}{n}}$ which yields a time-dependent deceleration parameter (DP) representing a new class of models that generate a transition of universe from the early decelerated phase to the recent accelerating phase. Exact solutions of Einstein's modified field equations with perfect fluid and heat conduction are obtained within the framework of Saez-Ballester scalar-tensor theory of gravitation and the model is found to be in good agreement with recent observations. We find, for n = 3, k = 1, the present value of DP in derived model as q_0 = -0.67 which is very near to the observed value of DP at present epoch. We find that the time-dependent DP is sensible for the present day Universe and give an earmark description of evolution of universe. Some physical and geometric properties of the models are also discussed.