Max-Planck-Institut für Gravitationsphysik,   Albert-Einstein-Institut

## Critical phenomena and the Aretakis instability of extremal black hole perturbations

 Starts at: Wed 23 Jan 2019, 14:00 Speaker: Peter Zimmerman Institute: Max Planck Institute for Gravitational Physics Pot Abstract: Perturbations of extremal black holes are asymptotically self-similar under the near-horizon, late-time scaling symmetry of the background metric. In this talk, I will explain why this effect is universal and how it accounts for the Aretakis instability $$growth of transverse derivatives$$ as a critical phenomenon associated with the emergent symmetry. Taking Kerr as an example, I will show how the decay of each perturbing mode is characterized by a critical exponent after defining suitable notions of weak and strong self-similarity. I will end with a simple argument for why all generally covariant scalar quantities decay to zero despite the growth of transverse derivatives. Seminartype: Ordinary Room: Seminarraum 0.01 Contact: Alexander Prostimkin