Relativistic isotropic stellar model with Durgapal-V metric in $f({R}, {T})$ gravity

TL;DR

This paper develops a new, non-singular relativistic model for static, isotropic compact stars within $f(R,T)$ gravity, analyzing stability, physical conditions, and the influence of the coupling parameter compared to general relativity.

Contribution

It introduces a novel $f(R,T)$ gravity-based stellar model using Durgapal-V metric, demonstrating stability and physical viability, and compares effects of the coupling constant with Einstein gravity.

Findings

Solutions are singularity-free at the center.

Model satisfies all energy and causality conditions.

Modified gravity provides more stable long-term stellar configurations.

Abstract

The main aim of this paper is to obtain a completely new relativistic non-singular model for static, spherically symmetric isotropic celestial compact stars in the $f(R, T)$ gravity scenario. In this regard, we have considered the isotropic Durgapal-V metric {\it ansatz} \cite{dur82} to find the solutions of Einstein's field equations in the framework of $f(R, T)$ gravity. The obtained solutions are analyzed graphically for the compact star {\it Cen X}-3 with mass $M$ = $ 1.49 \pm 0.08 ~ M_\odot$ and radius $R$ = 9.178 $\pm$ 0.13 $km$ \cite{ml11} and numerically for ten well-known different compact stars along with {\it Cen X}-3 corresponding to the different values of coupling constant $\chi$. The reported solutions are singularity-free at the center of the stars, physically well-behaved, and hold the physically stable matter configurations by satisfying all the energy conditions and EoS parameter $\omega(r) \in $ (0, 1), causality condition, adiabatic index $\Gamma(r) > 4/3$. We have also discussed hydrostatic equilibrium through the modified TOV equation to ensure the equilibrium position of the solutions representing matter distributions. Considering the several values of $\chi$ we have examined the impact of this parameter on the proposed solutions that help to make a fruitful comparison of modified $f(R, T)$ gravity to the standard general relativity, and interestingly, we have found that the modified $f(R, T)$ gravity holds long-term stable compact objects than the standard Einstein gravity. All the graphical and numerical results ensure that our reported model is under the physically admissible regime that indicates the acceptability of the model.