Speaker
Davide Perrone
(Universite de Geneve (CH))
Description
Quasi-normal modes are a crucial feature of black holes and their study is fundamental to understanding these objects. These excitations are not only linear but it has been shown to have a relevant non-linear counterpart, in general difficult to calculate.
The Penrose limit connects a plane wave geometry to the photon ring of a black hole, where the quasi-normal modes are located in the eikonal limit. With this simplification, we extract the quadratic-level non-linearities in the quasi-normal modes of a Schwarzschild black hole for the (ℓ×ℓ)→2ℓ channel.
This result is independent of ℓ, and the claim can be further confirmed through symmetry arguments.
Author
Davide Perrone
(Universite de Geneve (CH))
Co-authors
Alex Kehagias
Antonio Walter Riotto
(Universite de Geneve (CH))
