UC Santa Barbara

Black hole thermodynamics suggests that in order to describe the physics of distant observers, one may model a black hole as a standard quantum system with a density of states set by the Bekenstein–Hawking entropy [Formula: see text]. This idea has long been considered to be in strong tension with Hawking’s prediction that radiation from black holes is nearly thermal, and with low-energy gravity more generally. But the past two years have shown that low-energy gravity does offer a self-consistent description of black hole evaporation consistent with the above idea, and which in particular reproduces the famous Page curve. We provide a brief overview of this new paradigm, focusing on Lorentz-signature asymptotically-flat spacetimes and emphasizing operationally defined observables that probe the entropy of Hawking radiation.