PIRSA:16050045

Dynamics of Superrotations in 2+1 Dimensions

Carlip, S. (2016). Dynamics of Superrotations in 2+1 Dimensions. Perimeter Institute. https://pirsa.org/16050045

Carlip, Steve. Dynamics of Superrotations in 2+1 Dimensions. Perimeter Institute, May. 12, 2016, https://pirsa.org/16050045 

          @misc{ pirsa_PIRSA:16050045,
            doi = {10.48660/16050045},
            url = {https://pirsa.org/16050045},
            author = {Carlip, Steve},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Dynamics of Superrotations in 2+1 Dimensions},
            publisher = {Perimeter Institute},
            year = {2016},
            month = {may},
            note = {PIRSA:16050045 see, \url{https://pirsa.org}}
          }

Steve Carlip

University of California, Davis

Talk number
PIRSA:16050045
Collection
Talk Type
Subject
Abstract

General relativity is invariant under diffeomorphisms, and

excitations of the metric corresponding to diffeomorphisms

are nonphysical.  In the presence of a boundary, though --

including a boundary at infinity -- the Einstein-Hilbert

action with suitable boundary terms is no longer fully

invariant, and certain diffeomorphisms are promoted to

physical degrees of freedom.  After briefly describing how

this happens in (2+1)-dimensional AdS gravity, I will

report on work in progress on the asymptotically flat case,

for which the newly dynamical diffeomorphisms are the

superrotations, and the boundary action is related to

coadjoint orbits of the Virasoro group and Hill's equation.