Evidence for violations of Weak Cosmic Censorship in black hole collisions in higher dimensions

TL;DR

This study provides numerical evidence that black hole collisions in higher dimensions can lead to horizon instabilities and naked singularities, challenging the Weak Cosmic Censorship Conjecture.

Contribution

It demonstrates, for the first time, that generic black hole collisions in higher dimensions can violate the Weak Cosmic Censorship Conjecture through horizon pinch-off.

Findings

Unstable dumbbell-like black hole horizons form during collisions.

Horizon pinch-off occurs in finite asymptotic time, creating naked singularities.

Violations of Weak Cosmic Censorship are shown to be generic in higher dimensions.

Abstract

We study collisions of boosted rotating black holes in $D=6$ and 7 spacetime dimensions with a non-zero impact parameter. We find that there exists an open set of initial conditions such that the intermediate state of the collision is a black hole with a dumbbell-like horizon which is unstable to a local Gregory-Laflamme-type instability. We are able to provide convincing numerical evidence that the evolution of such an instability leads to a pinch off of the horizon in finite asymptotic time thus forming a naked singularity, as in similar unstable black holes. Since the black holes in the initial state are stable, this is the first genuinely generic evidence for the violation of the Weak Cosmic Censorship Conjecture in higher dimensional asymptotically flat spacetimes.