Evolution of expansion-free massive stellar object in f(R, T) gravity

This paper explores an expansion-free model of a cluster of stars in the f ( R , T ) gravity. We consider a dissipative anisotropic viscous model of the star cluster. The mathematical modeling of a cluster of stars involving field equations, junction condition and dynamical equations is presented. The circumferential and relative radial velocities of the evolving layers of fluids are used to describe the physical meaning of expansion and shear effects. It is concluded that the expansion-free evolution of the star cluster contains a vacuum cavity within it. The relative velocity between the neighboring layers of fluids determines the cluster’s expansion-free and shear-free collapse. The Skripkin model with constant density is equivalent to the non-dissipative expansion-free isotropic star cluster. For the shear-free scenario, this model demonstrates homologous evolution. Finally, it is found that the f ( R , T ) gravitational terms indicating dark matter’s contribution to a star cluster have a significant impact on the dynamics of expansion-free evolution.