Superradiant instability of black resonators and geons

Understand

Black resonators and geons in global AdS are rapidly rotating, low-energy solutions with a helical Killing field.

• We study the linear mode stability of equal angular momenta, five-dimensional black resonators and geons under scalar, electromagnetic, and gravitational perturbations.
• We find that black resonators are unstable to the superradiant instability, in agreement with previously known results.
• Perhaps surprisingly, many geons appear linearly stable, despite having an ergoregion.