Kadanoff Seminar: Semiclassical microstates. - Pushkal Shrivastava, Harvard University

The phase space of semiclassical excitations on a black hole background is divergent, with the expectation that this divergence should be regulated by the ultraviolet (UV) features of the theory. However, the mechanism responsible for this regulation remains unclear. 

This talk explores the semiclassical excitations within the framework of JT gravity with a dynamical end-of-the-world brane and matter. It will be demonstrated that, as anticipated, the phase space volume is divergent. However, upon imposing constraints on the "length", one obtains a finite phase space without the need of an explicit UV cutoff. Additionally, corresponding Euclidean configurations will be described.

The talk will conclude with speculative comments about higher dimensional black holes and potential UV features that could regulate the semiclassical divergence.