Non-Singular Black Holes and mass inflation in modified gravity

TL;DR

This paper derives a new class of non-singular, static black hole solutions in F(R)-gravity, analyzing their properties, particle motion, and the conditions under which mass inflation occurs or is avoided.

Contribution

It introduces a novel class of non-singular black hole metrics in F(R)-gravity and examines their geometric features and stability against mass inflation.

Findings

Non-singular black hole solutions without de Sitter cores.

Mass inflation occurs generally, except under extremal conditions.

Inner Cauchy horizon stability depends on specific extremal parameters.

Abstract

We analytically derive a class of non-singular, static and spherically symmetric topological black hole metrics inF(R)-gravity. These have not a de Sitter core at their centre, as most model in standard General Relativity. We study the geometric properties and the motion of test particles around these objects. Since they have two horizons, the inner being of Cauchy type, we focus on the problem of mass inflation and show that it occurs except when some extremal conditions are met.