How extreme are extreme black holes?

TL;DR

This paper investigates the properties of nearly extremal black holes formed by gravitational collapse, revealing that late-time horizon crossings lead to encountering a singularity rapidly.

Contribution

It demonstrates that nearly extremal black holes exhibit a rapid approach to singularity for late-time horizon crossings, providing new insights into their internal structure.

Findings

Observers crossing the horizon late encounter a singularity quickly

Nearly extremal black holes have distinct internal properties

The study enhances understanding of black hole internal dynamics

Abstract

We examine the properties of nearly extremal black holes produced by gravitational collapse. It is shown that an observer who crosses the black hole horizon at late times rapidly encounters a singularity.