Seminar

BMS3 representations, Virasoro coadjoint orbits and holographic positive energy theorems in 3d gravity

By
Glenn Barnich (Université Libre de Bruxelles)
Date
Place
Aula 507
seminar ICCUB
The symmetry groups of three and four dimensional asymptotically anti-de Sitter and flat spacetimes are discussed. In three dimensions, it is the conformal group in two dimensions, respectively the BMS group in three dimensions, which is the semi-direct product of the diffeomorphism group on the circle with its adjoint representation embedded as an abelian normal subgroup. We further show that the reduced phase space of these three dimensional gravity theories is completely described by the coadjoint representation of their symmetry groups. As a consequence, a series of natural questions in 3d gravity can be phrased and answered in terms of the well-known classification of Virasoro coadjoints orbits and their properties.