Regular black holes with stable cores

TL;DR

This paper investigates the stability of regular black holes with non-singular cores, showing that certain solutions remain stable by controlling mass inflation and curvature growth at the inner horizon.

Contribution

It provides a detailed analysis of the dynamics of regular black holes with full backreaction, demonstrating stability features in Hayward and Asymptotic Safety solutions.

Findings

Regular black holes can have stable cores with controlled mass inflation.

Hayward and Asymptotic Safety solutions satisfy stability criteria.

Inner horizons in these models are rendered stable against classical instabilities.

Abstract

Non-singular black hole geometries typically come with two spacetime horizons: an (outer) event horizon and an (inner) Cauchy horizon. This nurtures the speculation that they may be subject to a mass-inflation effect which renders the Cauchy horizon unstable. We analyze the dynamics associated with spherically symmetric, regular black holes taking the full backreaction between the infalling matter and geometry into account. On this basis, we identify the crucial features taming the growth of the mass function and diminishing the curvature singularity at the Cauchy horizon. It is demonstrated explicitly that the regular black hole solutions proposed by Hayward and obtained from Asymptotic Safety satisfy these properties.