Dynamical Instability of Spherical Star in $f(R,T)$ gravity
  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. 
Ifra Noureen and M. Zubair
physics.gen-ph