String Theory seminar - Andrea Legramandi Seminar

Abstract: We consider the island formula for the entropy of an arbitrary subset of the Hawking radiation in the adiabatic limit, including the effect of a grey-body factor. We find a simple concrete ‘on-shell’ formula for the generalized entropy which involves the image of the island out in the stream of radiation, the ‘island in the stream’. The quantum information properties of the radiation are discussed together with the entanglement monogamy problem. The grey-body factor allows us to analyse the role of irreversibility in the evaporation. In particular, we show that irreversibility leads to multiple saddles to dominate the entropy, and we will match this result with a generalization of Page's theorem that involves a nested temporal sequence of unitary averages.