Superstrings near the conformal boundary of AdS3

A bstract We study worldsheet sphere amplitudes, in the RNS formalism, in superstring theory on AdS 3 × X with pure NS-NS flux using the near-boundary approximation. By computing a number of amplitudes at low-lying spectral flow, we deduce a candidate for a dual CFT for generic X . Specialising to X = S 3 × 𝕋 4 and with minimal NS-NS flux, i.e., to the tensionless limit, we explore the effect of the interaction term which we ignore in the near-boundary consideration. We show, under some assumptions, that amplitudes in the tensionless superstring theory on AdS 3 × S 3 × 𝕋 4 do not receive perturbative contributions from such an interaction term.