The Black Ring is Unstable

Understand

We study non-axisymmetric linearised gravitational perturbations of the Emparan-Reall black ring using numerical methods.

• We find an unstable mode whose onset lies within the "fat" branch of the black ring and continues into the "thin" branch.
• Together with previous results using Penrose inequalities that fat black rings are unstable, this provides numerical evidence that the entire black ring family is unstable.