Evolution of Axially Symmetric Anisotropic Sources in $f(R,T)$ Gravity

TL;DR

This paper analyzes the stability of axially symmetric, anisotropic self-gravitating systems in $f(R,T)$ gravity, focusing on how matter-geometry coupling affects instability ranges in Newtonian and post-Newtonian regimes.

Contribution

It formulates the dynamical equations for axially symmetric anisotropic sources in $f(R,T)$ gravity and investigates their stability under perturbations.

Findings

Derived the evolution equation involving adiabatic index $\Gamma$.

Identified the impact of matter-geometry coupling on instability ranges.

Analyzed stability conditions in Newtonian and post-Newtonian approximations.

Abstract

We discuss the dynamical analysis in $f(R,T)$ gravity (where $R$ is Ricci scalar and $T$ is trace of energy momentum tensor) for gravitating sources carrying axial symmetry. The self gravitating system is taken to be anisotropic and line element describes axially symmetric geometry avoiding rotation about symmetry axis and meridional motions (zero vorticity case). The modified field equations for axial symmetry in $f(R,T)$ theory are formulated, together with the dynamical equations. Linearly perturbed dynamical equations lead to the evolution equation carrying adiabatic index $\Gamma$ that defines impact of non-minimal matter to geometry coupling on range of instability for Newtonian (N) and post-Newtonian (pN) approximations.