Black holes die hard: can one spin-up a black hole past extremality?

TL;DR

This paper investigates whether spinning up black holes beyond extremality is possible by throwing particles with high angular momentum, and finds that such attempts do not succeed across various black hole geometries, supporting Cosmic Censorship.

Contribution

The study extends the analysis of black hole destruction via particle capture to higher-dimensional black holes and black rings, confirming the robustness of Cosmic Censorship.

Findings

High angular momentum particles are not captured by various black hole types.

Black holes cannot be spun up past extremality through this process.

Cosmic Censorship remains valid in extended black hole geometries.

Abstract

A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for a variety of black hole geometries, from black holes in higher dimensions to black rings. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.