Date/Time:28 Mar 2019 16:00Venue: S17 #05-12 SR4Speaker: Dejan Gajic, University of CambridgeQuasinormal modes on black hole spacetimesA fundamental problem in the context of Einstein’s equations of general relativity is to understand the evolution of small perturbations of stationary black hole solutions. It is expected that there is a discrete set of characteristic frequencies that play a dominant role at late times and carry information about the nature of the black hole, similar to the normal frequencies of a vibrating guitar string. These frequencies are called quasinormal frequencies and they are closely related to scattering resonances in the study of Schrödinger’s equation. I will consider the linear wave equation on black hole backgrounds as a toy model for the Einstein equations and give an introduction to quasinormal frequencies in this setting. Then I will discuss a new method of defining and studying quasinormal frequencies on asymptotically flat spacetimes, developed from joint work with Claude Warnick, which interprets the frequencies as honest eigenvalues of a natural operator acting on a Hilbert space.Add to calendar: