3–5 juin 2026
Tours
Fuseau horaire Europe/Paris

Talks

Sebastian Gurriaran

Title: Non-linear instability of the Kerr Cauchy horizon near timelike infinity

Abstract: The Kerr metrics model rotating vacuum black holes, and are expected to play a central role in the long-time description of generic solutions to the Einstein vacuum equation. They present the disturbing feature that determinism breaks down inside the black hole, beyond the Cauchy horizon. Penrose's Strong Cosmic Censorship conjecture states that this behavior is however unstable and vanishes upon small perturbations. I will present a recent work which proves that, assuming a non-linear Price's law-type estimate near the event horizon, in generic perturbations of Kerr black holes ruled by the full, non-linear, Einstein vacuum equation, a singularity forms at the Cauchy horizon near timelike infinity. This singularity - at the Lipschitz level for the metric - prevents the unphysical extensions and recovers determinism.

Alexandros Kehagias

Title: The AdS Perspective on the Nonlinear Tails in Black Hole Ringdown
 
Abstract: Black holes gradually settle into their static configuration by emitting gravitational waves, whose amplitude diminish over time according to a power-law decay at fixed spatial locations. We show that the nonlinear tails in the presence of a quadratic source, which have been recently found to potentially dominate over the linear ones, can be simply derived from the AdS_2 × S^2 spacetime perspective with their amplitudes being related to the Aretakis constants.