Horizons and singularity in Clifton's spherical solution of f(R) vacuum

TL;DR

This paper analyzes Clifton's exact spherical solution in f(R) gravity, revealing that apparent horizons vanish and a naked singularity forms over time, highlighting dynamical black hole behavior in such theories.

Contribution

It provides a detailed study of Clifton's solution, demonstrating horizon disappearance and singularity emergence, advancing understanding of dynamical black holes in f(R) gravity.

Findings

Apparent horizons disappear at late times.

A naked singularity emerges in the solution.

Black hole dynamics differ from general relativity.

Abstract

Due to the failure of Birkhoff's theorem, black holes in f(R) gravity theories in which an effective time-varying cosmological "constant" is present are, in general, dynamical. Clifton's exact spherical solution of R^(1+\delta) gravity, which is dynamical and describes a central object embedded in a spatially flat universe, is studied. It is shown that apparent black hole horizons disappear and a naked singularity emerges at late times.