Date : December 7, 2021, 16:00 CET

Ben Freivogel (U. of Amsterdam)


Title: Computing Quantum Corrections to Black Holes in Semi-Classical Gravity

Abstract: Based mainly on [arXiv:2105.12771]. An important question about black holes is to what extent a typical pure state differs from the ensemble average. We show that this question can be answered within semi-classical gravity. We focus on the quantum deviation, which measures the fluctuations in the expectation value of an operator in an ensemble of pure states. For a large class of ensembles and observables, these fluctuations are calculated by a correlation function in the eternal black hole background, which can be reliably calculated within semi-classical gravity. This implements the idea of [arXiv:2002.02971] that wormholes can arise from averages over states rather than theories. As an application, we calculate the size of the long-time correlation function ⟨A(t)A(0)⟩.