Entanglement of spacetime

Speaker

William Donnelly

Abstract

Entanglement is both a central feature of quantum mechanics and a powerful tool for studying quantum systems. Even empty spacetime is a highly entangled state, and this entanglement has the potential to explain puzzling thermodynamic properties of black holes. In order to apply the methods of quantum information theory to problems in gravity we have to confront a more fundamental question: what is a local subsystem, and what are its physical degrees of freedom? I will show that local subsystems in gravity come with new physical degrees of freedom living on the boundary, as well as new physical symmetries. These structures offer us new insight into how spacetime is entangled, and a new perspective on the problem of quantizing gravity.