Dynamical Transition from a Naked Singularity to a Black Hole

TL;DR

This paper demonstrates that a Reissner-Nordström naked singularity can dynamically transition into a black hole through the accretion of a charged dust shell, supporting cosmic censorship and analyzing the process's causal structure.

Contribution

It provides a novel dynamical mechanism showing how a naked singularity can evolve into a black hole, which was previously thought to be prohibited.

Findings

RN naked singularity can be converted into a black hole by charged dust shell infall

Extreme RN black holes can form from naked singularities in finite time

The process supports the cosmic censorship conjecture

Abstract

We show that a Reissner-Nordstr\"{o}m (RN) black hole can be formed by dropping a charged thin dust shell onto a RN naked singularity. This is in contrast to the fact that a RN naked singularity is prohibited from forming by dropping a charged thin dust shell onto a RN black hole. This implies the strong tendency of the RN singularity to be covered by a horizon in favour of cosmic censorship. We show that an extreme RN black hole can also be formed from a RN naked singularity by the same process in a finite advanced time. We also discuss the evolution of the charged thin dust shells and the causal structure of the resultant spacetimes.