Higher genus correlators for tensionless AdS3 strings

It was recently shown in 1 that tree-level correlation functions in tensionless string theory on AdS3 × S3 × T4 match the expected form of correlation functions in the symmetric orbifold CFT on T4 in the large N limit. This analysis utilized the free-field realization of the psu(1 1 | 2) 1 Wess-Zumino-Witten model, along with a surprising identity directly relating these correlation functions to a branched covering of the boundary of AdS3. In particular, this identity implied the unusual feature that the string theory correlators localize to points in the moduli space for which the worldsheet covers the boundary of AdS3 with specified branching near the insertion points. In this work we generalize this analysis past the tree-level approximation, demonstrating its validity to higher genus worldsheets, and in turn providing strong evidence for this incarnation of the AdS/CFT correspondence at all orders in perturbation theory.