VSI seminar Wout Merbis

Title:
Three dimensional gravity and the orbit method

Abstract:
Three dimensional gravity has been a fruitful arena to address conceptual questions in quantum gravity. We will revisit pure quantum gravity in 3d, following the approach of first implementing constraints and then quantizing, as advocated by Coussaert, Henneaux and van Driel some time ago. This led them to reduce pure AdS3 gravity to Liouville theory. We will reconsider this derivation taking special care of zero-mode solutions representing BTZ black holes. We find a surprising connection between gravity in 3d and a piece of group theory known as the orbit method. The boundary dynamics of three dimensional gravity can be understood as the geometric quantization on the coadjoint orbit of the Virasoro group. We’ll comment on supergravity and gravity in three dimensional flat space.