Dynamical analysis of radiating spherical collapse in Palatini f(R) gravity

Abstract

We discuss dynamical instability of non-adiabatic anisotropic collapse of spherical self-gravitating systems through collapse equation in Palatini f(R) gravity. We take R+ϵRn model and assume hydrostatic equilibrium of celestial object at large past time such that T(−∞)=0. Considering perturbation from hydrostatic phase, and linearizing the dynamical as well as field equations, we evaluate instability constraints at Newtonian as well as post-Newtonian approximations. We conclude that pressure and heat flow assist collapsing phenomenon while Palatini f(R) dark source terms affect dynamics of self-gravitating object due to its non-attractive nature through stiffness parameter.