Cosmic censorship violation in black hole collisions in higher dimensions

Understand

We argue that cosmic censorship is violated in the collision of two black holes in high spacetime dimension D when the initial total angular momentum is sufficiently large.

• The two black holes merge and form an unstable bar-like horizon, which grows a neck in its middle that pinches down with diverging curvature.
• When D is large, the emission of gravitational radiation is strongly suppressed and cannot spin down the system to a stable rotating black hole before the neck grows.
• The phenomenon is demonstrated using simple numerical simulations of the effective theory in the 1/D expansion.