Black holes with a single Killing vector field: black resonators

TL;DR

This paper constructs novel asymptotically AdS black hole solutions with a single Killing vector, called black resonators, revealing their connection to superradiant instability, non-uniqueness, and their instability as potential endpoints.

Contribution

It introduces black resonators as new solutions linking superradiance and turbulence in AdS, and explores their properties and stability.

Findings

Black resonators share asymptotic charges with Kerr-AdS.

Black resonators have higher entropy than Kerr-AdS.

They are unstable, affecting superradiant instability endpoints.

Abstract

We numerically construct asymptotically anti-de Sitter (AdS) black holes in four dimensions that contain only a single Killing vector field. These solutions, which we coin black resonators, link the superradiant instability of Kerr-AdS to the nonlinear weakly turbulent instability of AdS by connecting the onset of the superradiance instability to smooth, horizonless geometries called geons. Furthermore, they demonstrate non-uniqueness of Kerr-AdS by sharing asymptotic charges. Where black resonators coexist with Kerr-AdS, we find that the black resonators have higher entropy. Nevertheless, we show that black resonators are unstable and comment on the implications for the endpoint of the superradiant instability.