What Do We Know About a Black Hole After Half Evaporation?

by Sebastian Zell (EPFL - Ecole Polytechnique Federale Lausanne (CH))

Wednesday 13 Jul 2022, 16:30 → 18:30 Europe/Zurich

4/3-006 - TH Conference Room (CERN)

Hawking's calculation of particle production by a black hole is based on the semi-classical limit of a fixed metric. Since this approximation may break down once the mass decreases significantly, I shall argue that the fate of a black hole after half evaporation is an open question. In an attempt to answer it, I will subsequently present a simple analogue system, which shares the information-processing properties of a black hole such as its Gibbons-Hawking entropy. An explicit computation of time evolution reveals indications that black hole evaporation slows down drastically at the latest after half of the mass is lost. This open up a new window for small primordial black holes as viable dark matter candidates. Finally, I will give an outlook to observational constraints.

Based on:
G. Dvali, L. Eisemann, M. Michel, S. Zell, Black hole metamorphosis and stabilization by memory burden, Phys. Rev. D 102 (2020) 103523, arXiv:2006.00011.