Dynamical Instability of Spherical Star in $f(R,T)$ gravity

TL;DR

This paper analyzes the stability of spherical stars in $f(R,T)$ gravity, deriving conditions for stability and instability during collapse, and compares results with $f(R)$ gravity.

Contribution

It introduces a stability analysis framework for spherically symmetric stars in $f(R,T)$ gravity, including collapse equations and stability conditions.

Findings

Conditions on adiabatic index $\Gamma$ for stability in Newtonian and post-Newtonian regimes

Constraints on physical quantities for stable stellar configurations

Results align with $f(R)$ gravity in specific cases

Abstract

This work is based on stability analysis of spherically symmetric collapsing star surrounding in locally anisotropic environment in $f(R,T)$ gravity, where $R$ is Ricci scalar and $T$ corresponds to the trace of energy momentum tensor. Field equations and dynamical equations are presented in the context of $f(R,T)$ gravity. Perturbation schem is employed on dynamical equations to find the collapse equation. Furthermore, condition on adiabatic index $\Gamma$ is constructed for Newtonian and post-Newtonian eras to address instability problem. Some constraints on physical quantities are imposed to maintain stable stellar configuration. The results in this work are in accordance with $f(R)$ gravity for specific case.