Appears in collection : Coherent states and their applications: a contemporary panorama / Etats cohérents et leurs applications : un panorama contemporain

Conventional quantum field theory techniques do not work for extracting physical information from a background-independent quantum theory of gravity. A technique that works is Oeckl's boundary formalism, with semiclassical coherent states on the boundary. I illustrate how this technique has allowed us to compute the lifetime of a black hole in loop quantum gravity. This is an astrophysical relevant quantity that could have observational consequences.