Black Hole Ringdown beyond Linear theory

by Bruno Bucciotti (Arizona State U.)

Wednesday 8 Jul 2026, 14:30 → 16:30 Europe/Rome

1/1-3 - Aula B (Dipartimento di Fisica e Astronomia - Edificio Marzolo)

Black hole quasi-normal modes (QNMs) dominate the ringdown phase of the gravitational-wave signal following black hole binary mergers, and their precise measurement underpins black hole spectroscopy. In this talk, I will review recent progress in our understanding of the Green's function for spin-2 perturbations of a broad class of black hole spacetimes. I will then discuss how nonlinearities modify the ringdown through mode coupling and the excitation of second-order QNMs, before concluding with recent work exploring how astrophysical environments may shift QNM frequencies.