Virtual Seminar Series | Claude Warnick, Cambridge University "Quasinormal modes of black holes"

During its ringdown phase a perturbed black-hole produces radiation at characteristic (complex) frequencies, much like the normal frequencies of a guitar string. These quasinormal frequencies carry information about the geometry of the black hole. In this talk I will review the problem of finding quasinormal frequencies, and discuss recent work which realises quasinormal frequencies as eigenvalues of a natural non-self adjoint operator associated with time evolution.