Gravity seminar - Dominic Dold Seminar

Asymptotically anti-de Sitter spacetimes have drawn considerable attention in the physics community within the last decade. In the study of classical General Relativity, understanding the stability of asymptotically AdS spacetimes is very different from the asymptotically flat case due to the timelike nature of null infinity. We will focus on the dynamics of the Klein-Gordon equation on Kerr-AdS spacetimes for various ranges of the spacetime parameters, in particular we will present our recent result which establishes the existence of exponentially growing mode solutions in the superradiant regime. This proves a conjecture of Hawking and Reall from 1999 and provides a first rigorous construction of unstable mode solution for negative cosmological constant. We will contrast this with known results about the massless and massive wave equation in Kerr spacetimes.