Self-force as a cosmic censor

TL;DR

This paper investigates whether electromagnetic self-force prevents near-extremal black holes from becoming overcharged when absorbing charged particles, supporting the idea that self-force acts as a cosmic censor.

Contribution

It incorporates electromagnetic self-force and radiation effects into the analysis, providing evidence that these factors prevent black hole destruction in such scenarios.

Findings

No overcharged black hole states found in parameter space

Self-force acts as a cosmic censor preventing black hole destruction

Results support the third law of black-hole mechanics

Abstract

We examine Hubeny's scenario according to which a near-extremal Reissner-Nordstr\"om black hole can absorb a particle and be driven toward an over-extremal state in which the charge exceeds the mass, signaling the destruction of the black hole. Our analysis incorporates the particle's electromagnetic self-force and the energy radiated to infinity in the form of electromagnetic waves. With these essential ingredients, our sampling of the parameter space reveals no instances of an overcharged final state, and we conjecture that the self-force acts as a cosmic censor, preventing the destruction of a near-extremal black hole by the absorption of a charged particle. We argue, on the basis of the third law of black-hole mechanics, that this conclusion is robust and should apply to attempts to overspin a Kerr black hole.