Mathematical Physics Seminar

We discuss long time behavior of linear scalar waves on Kerr
and Kerr-de Sitter black hole backgrounds and their stationary perturbations. The
physical motivation comes from the analysis of gravitational waves emitted during the ringdown
stage of a large scale event (such as merging with another black hole). The properties of these
waves, and their frequencies, called quasi-normal modes or resonances, depend on the
structure of the set of all trapped light rays. In the considered Kerr(-de Sitter) case, the trapped set is r-normally hyperbolic and we can provide a detailed description of quasi-normal modes and long-time behavior of linear waves.