La forme de l'espace, des trous noirs au multivers
By Jean-Pierre Luminet
Des oscillations de Fourier aux ondes gravitationnelles : la théorie analytique de la propagation de l'information
By Ronald Coifman
Appears in collection : Summer School 2014 - Asymptotic Analysis in General Relativity
Motivated by wave decay for Kerr and Kerr‐de Sitter black holes, we study spectral gaps for codimension 2 normally hyperbolic trapped sets with smooth stable/unstable foliations. Using semiclassical defect measures, we recover the gap of Wunsch‐Zworski and Nonnenmacher‐Zworski in our case. Under the stronger assumptions of r-normal hyperbolicity and pinching, we discover further spectral gaps, meaning that resonances are stratified into bands by decay rates.