Can quantum mechanics fool the cosmic censor?

TL;DR

This paper examines whether quantum effects can enable the violation of the weak cosmic censorship conjecture by overspinning nearly-extreme charged black holes through tunneling particles, and finds quantum processes may bypass classical censorship.

Contribution

It demonstrates that large angular momentum particles can quantum mechanically overspin black holes without classical back-reaction preventing it, challenging classical views of cosmic censorship.

Findings

Quantum tunneling can overspin black holes despite classical back-reaction.

Large angular momentum does not prevent quantum overspinning.

Quantum effects may allow violations of the weak cosmic censorship conjecture.

Abstract

We revisit the mechanism for violating the weak cosmic-censorship conjecture (WCCC) by overspinning a nearly-extreme charged black hole. The mechanism consists of an incoming massless neutral scalar particle, with low energy and large angular momentum, tunneling into the hole. We investigate the effect of the large angular momentum of the incoming particle on the background geometry and address recent claims that such a back-reaction would invalidate the mechanism. We show that the large angular momentum of the incident particle does not constitute an obvious impediment to the success of the overspinning quantum mechanism, although the induced back-reaction turns out to be essential to restoring the validity of the WCCC in the classical regime. These results seem to endorse the view that the "cosmic censor" may be oblivious to processes involving quantum effects.