Orateur
Description
The quasinormal-mode spectrum of a horizonless compact object can differ significantly from that of the corresponding classical black hole. However, the time response can be initially very similar if the object is sufficiently compact. A generic smoking gun of the absence of a classical horizon is the presence of echoes in the late-time ringdown. The echo delay time and morphology depend crucially on the properties of the object down to its potential well. Most of the echo analyses so far have considered toy or phenomenological models. I will present recent results on the ringdown phenomenology for a class of multicenter geometries describing the microstates of a static BPS black hole. The numerical method is based on numerical-relativity simulations of a test scalar field propagating on these geometries and can be applied to any stationary microstate, including non-BPS ones.
https://youtu.be/cYAoByDykTE
