Dark Energy Nature in Logarithmic $f(R,T)$ Cosmology

TL;DR

This paper explores a logarithmic $f(R,T)$ gravity model in a flat universe, deriving field equations, constraining parameters with observational data, and showing it models dark energy consistent with quintessence and approaching $ ext{Lambda}$CDM.

Contribution

It introduces a novel logarithmic $f(R,T)$ gravity model, derives its field equations, and constrains it with observational data to explain dark energy behavior.

Findings

Model exhibits quintessence dark energy behavior.

Late-time universe approaches $ ext{Lambda}$CDM.

Constraints align with observational datasets.

Abstract

The present research paper is an investigation of dark energy nature of logarithmic $f(R, T)$-gravity cosmology in a flat FLRW space-time universe. We have derived modified Einstein's field equations for the function $f(R, T)=R-16\pi G\alpha\ln(T)$ where $R$ is the Ricci scalar curvature, $T$ is the trace of the stress energy momentum tensor and $\alpha$ is a model parameter. We have solved field equations in the form of two fluid scenario as perfect-fluid and dark-fluid, where dark fluid term is derived in the form of perfect fluid source. We have made an observational constraints on the cosmological parameters $\Omega_{(m)}, \omega^{(de)}$ and $H_{0}$ using $\chi^{2}$ test with observational datasets like Pantheon sample of SNe Ia and $H(z)$. With these constraints we have discussed our model with deceleration parameter $q$, energy parameters $\Omega_{(m)}, \Omega_{(de)}$, EoS parameter $\omega^{(de)}$ etc. Also, we have done Om diagnostic analysis. The derived $f(R, T)$ model shows a quintessence dark energy model $\omega^{(de)}>-1$ and late-time universe approaches to $\Lambda$CDM model.