FTheory: Oscillations of Rapidly Rotating Black Holes
Perturbed black holes ring down through a set of decaying resonances known as quasinormal modes. When black holes spin at nearly their maximum rate, these modes have approximately integer frequency spacing and decay slowly, which leads to characteristic effects during ringdown. These include the collective ringing of modes, transient growth of perturbations, and the possibility of parametric resonances. I will discuss these unique dynamics and their possible consequences.