BPS Correlators for $\text{AdS}_3/\text{CFT}_2$

TL;DR

This paper demonstrates the matching of BPS correlators between the symmetric product orbifold and the dual worldsheet theory in AdS3/CFT2, providing a clearer understanding of the duality at minimal flux and extending to descendants.

Contribution

It explicitly reproduces symmetric orbifold BPS correlators from the worldsheet theory and generalizes the approach to arbitrary descendants using DDF operators.

Findings

Matching of BPS correlators between orbifold and worldsheet theories

Identification of worldsheet duals via lift to covering surface

Extension of the method to arbitrary descendants

Abstract

The BPS correlators of the symmetric product orbifold $\text{Sym}_N(\mathbb{T}^4)$ are reproduced from the dual worldsheet theory describing strings on $\text{AdS}_3\times {\rm S}^3\times \mathbb{T}^4$ with minimal ($k=1$) NS-NS flux. More specifically, we show that the worldsheet duals of the symmetric orbifold BPS states can be identified with their lift to the covering surface, thereby making the matching of the correlators essentially manifest. We also argue that the argument can be generalised to arbitrary descendants, using suitable DDF operators on the worldsheet.