Title: “Entanglement entropies of equilibrated pure states and the origin of replica wormholes”
Abstract:
I will explain an approximation method that gives a simple universal expression for the Renyi entropies of an equilibrated pure state in a chaotic quantum many-body system. This expression is independent of the details of the initial state and hence reflects thermalization, while also being manifestly consistent with unitarity. I will discuss how applying this method to models of evaporating black holes leads to a derivation of replica wormholes, which have recently been used to address the information loss paradox in these models. More generally, this approach elucidates the role played by Euclidean path integrals in calculations of time-evolved Renyi entropies. It also helps address the question of whether an average over theories is needed in order to explain results from replica wormholes.
Slides: