Talk detail

Participant	Roy, Debraj
Institution	SN Bose National Centre for Basic Sciences - Bloack JD, Sector 3, Salt Lake, - Kolkata - West Bengal - India

Session	GT3	Accepted	Yes	Order	6	Time	15:15
Talk	Oral abstract	Title	Trivial symmetries in 3-d models of gravity, a hamiltonian analysis
Co-authors	Rabin Banerjee
Abstract	We perform a systematic construction of off-shell gauge symmetries of 3-D gravity actions in a total hamiltonian formalism. Since the systems analysed are models of gravity (in Riemann-Cartan spacetime with torsion), there is an underlying Poincare symmetry, also off-shell. Comparison is made between this underlying Poincare symmetry and the hamiltonian symmetries constructed systematically. Though both the symmetries are themselves off-shell, it has been noted in literature that the two symmetries become equivalent only on-shell. But does this imply that there are really two independent sets of symmetries? We show here that the hamiltonian and Poincare symmetries are actually equivalent to each other, modulo trivial gauge symmetries. The gauge identities corresponding to the symmetries are also discussed and some subtle issues like use of field-dependent maps between gauge parameters are commented upon.