Regular black hole with sub-Planckian curvature and suppressed exponential mass inflation

TL;DR

This paper presents a new regular black hole model with a Minkowski core and a degenerate inner horizon, maintaining sub-Planckian curvature and suppressing exponential mass inflation.

Contribution

The authors construct a static spherically symmetric regular black hole with unique features like a Minkowski core and controlled curvature, reducing mass inflation effects.

Findings

Curvature remains sub-Planckian everywhere by choosing inner horizon radius.

Inner horizon amplification is softened from exponential to power-law.

Internal mass remains finite at late times, approaching r_-/2.

Abstract

We construct a static spherically symmetric regular black hole with a Minkowski core, and a degenerate inner horizon with vanishing surface gravity. The spacetime contains a non-extremal outer horizon and exhibits two notable features. Firstly, in the large-mass regime with $r_+=2M$, the Kretschmann scalar becomes nearly independent of the ADM mass and is mainly controlled by the inner horizon radius $r_-$, so that the curvature of spacetime remains sub-Planckian everywhere by choosing $r_-$ appropriately. Secondly, the near inner horizon amplification is softened from exponential to power-law behavior. In particular, within the double-null shell and Ori models, the internal Misner-Sharp mass remains finite at late times and approaches $r_-/2$.