Expansionfree Fluid Evolution and Skripkin Model in f(R) Theory

TL;DR

This paper explores the dynamics of spherically symmetric star collapse in f(R) gravity, focusing on expansionfree evolution and the Skripkin model, revealing differences from General Relativity due to curvature fluid effects.

Contribution

It introduces a detailed analysis of gravitational collapse in f(R) gravity with expansionfree conditions, extending the Skripkin model to modified gravity.

Findings

Modified dynamical equations and junction conditions in f(R) gravity.

Comparison shows differences from General Relativity results.

Insights into the role of curvature fluid in collapse dynamics.

Abstract

We consider the modified $f(R)$ theory of gravity whose higher order curvature terms are interpreted as a gravitational fluid or dark source. The gravitational collapse of a spherically symmetric star, made up of locally anisotropic viscous fluid, is studied under the general influence of the curvature fluid. Dynamical equations and junction conditions are modified in the context of f(R) dark energy and by taking into account the expansionfree evolution of the self-gravitating fluid. As a particular example, the Skripkin model is investigated which corresponds to isotropic pressure with constant energy density. The results are compared with corresponding results in General Relativity.