Correlators for tensionless strings on ${\rm AdS}_3$ orbifolds

TL;DR

This paper demonstrates that correlators in tensionless string theory on AdS3 orbifolds match the dual CFT predictions at leading order, confirming the duality beyond spectrum analysis.

Contribution

It extends previous spectrum results by showing correlators also agree at leading order, strengthening the AdS3/CFT2 duality understanding.

Findings

Correlators match between worldsheet theory and dual CFT at leading order.

Supports the duality between tensionless strings on AdS3 and symmetric orbifold CFT.

Confirms the correspondence beyond spectrum to include correlator structure.

Abstract

The CFT dual of string theory on $({\rm AdS}_3 \times {\rm S}^3)/\mathbb{Z}_k\times \mathbb{T}^4$ is believed to be described by the subspace of the symmetric orbifold of $\mathbb{T}^4$ that comprises the low-lying excitations on top of a certain reference state. (This `non-perturbative' reference state lies in the twisted sector associated to the conjugacy class consisting of only $k$-cycles.) In a recent paper we confirmed this picture by analysing the worldsheet theory of the orbifold at the tensionless NS-NS point, and by showing that the perturbative worldsheet spectrum reproduces precisely the single particle excitations on top of this reference state. In this paper we explain that this identification also holds on the level of the correlators, at least to leading order in $1/N$.