High Energy Theory Seminar

The claim that quantum gravity effects destroy the classical black hole horizon and has to be replaced by a firewall or horizon-scale structure is rather bold but is supported in string theory. I will discuss signs of this breakdown of effective field theory at the horizon of supersymmetric and Schwarzschild black holes and how the very ingredients of string theory - (anti)branes, topology and fluxes - can be used to build horizon-scale structure. The stability of antibranes in flux backgrounds which has been called into question in recent years will be addressed. An important outstanding problem about dynamics is to understand if and how a collapsing star can evolve into horizon-size structure rather than forming a horizon. To address this I will study quantum tunneling into black hole microstate geometries which is similar to - but differs in key points from - estimates of lifetimes of metastable states in backgrounds relevant for gauge/gravity duality, and discuss features of their typical tunneling end states.