Superstrings near the conformal boundary of $\mathrm{Ad}{\mathrm{S}}_3$

Abstract

We study worldsheet sphere amplitudes, in the RNS formalism, in superstring theory on ${\text{AdS}}_3\times X$ 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 $X={\mathrm{S}}^3\times {\mathbb{T}}^4$ 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 that amplitudes in the tensionless superstring theory on $\mathrm{Ad}{\mathrm{S}}_3\times {\mathrm{S}}^3\times {\mathbb{T}}^4$ do not receive perturbative contributions from such an interaction term.