Abstract: (2+1)-dimensional gravity allows us to study aspects of classical and quantum gravity in a simpler technical setting which retains much of the conceptual complexity of the standard (3+1)-dimensional gravity. However, pure Einstein gravity lacks propagating degrees of freedom in 2+1 dimensions. Topologically Massive Gravity is a deformation of GR which includes propagating degrees of freedom. Besides the famous BTZ black hole solution, this theory has a whole new class of black hole solutions -- the warped AdS3 black holes -- which can be viewed as deformed BTZ solutions but which, counterintuitively, are not asymptotically AdS -- they are actually (almost) asymptotically flat!
In this talk, I will describe the issue of mode stability of this interesting set of solutions. I will show that, in contrast with the Kerr black hole, the warped AdS3 black hole is classically stable to massive scalar field perturbations, by analysing its mode stability.
This work has been published in Phys. Rev. D 87, 124013 (2013).