Speaker: Jnanadeva Maharana (Bhubaneswar, NISER)

Title: Ward Identities in String Theory

Abstract:
It is well known that string theories are very rich in symmetry contents. I shall focus on massless sector of closed bosonic string. The effective action is known to be invariant under general coordinate
transformations and under ‘vector’ gauge transformation of 2-form potential. For compactified closed string it admits nonabelian gauge invariance associated with massless gauge excitations. These symmetries are not exhibited by the worldsheet action which respects two-dimensional diffeomorphism invariance. I shall show how the abovementioned target space local symmetries can be studied in Hamiltonian formulation of the theory in the worldsheet.
There are some shortcomings and I shall propose possible resolutions.