Massive scalar wave packet emission by a charged Black Hole and Cosmic Censorship Conjecture violation

TL;DR

This paper investigates the quantum tunneling of massive scalar particles from near-extremal charged black holes and finds that, while violations of the cosmic censorship conjecture are theoretically possible, they are practically unobservable due to rapid discharge processes and time dilation effects.

Contribution

It demonstrates the theoretical possibility of cosmic censorship violation via scalar wave emission from charged black holes, considering realistic discharge and time dilation effects.

Findings

Tunneling probability for massive scalar particles is non-zero.

Black holes tend to discharge faster than the tunneling process.

Observable violations of cosmic censorship are effectively prevented.

Abstract

We study the tunneling probability of a massive ($m_w$) uncharged scalar packet out from a near-extremal, static charged black hole (with mass $M$ and charge $Q\lesssim M$). We show that there is indeed a net probability that a massive uncharged particle tunnels out from the black hole so that the final state (with new mass $M'\equiv M-m_w < Q$) does violate the cosmic censorship conjecture. Nevertheless, the typical time for such a black hole to discharge (i.e, to absorb charge $-Q$ from its surroundings and then become neutral) is much smaller than the tunneling time; therefore, the violation is never attained in practice. Even for a completely isolated black hole (should it exist), the standard time dilation near the horizon stretches the typical violation time scale to unobservable values.