Massless S matrices for AdS3/CFT2

TL;DR

This paper analyzes the massless excitations in the AdS3/CFT2 correspondence, focusing on their chiral split and the constraints on the two-particle S matrix imposed by symmetries and invariances.

Contribution

It provides a detailed study of massless modes in AdS3/CFT2, highlighting their chiral structure and deriving symmetry constraints on the worldsheet S matrix.

Findings

Massless modes naturally split into chiral and anti-chiral representations.

Constraints on the S matrix from braiding, unitarity, and invariances are established.

Implications for mirror kinematics are discussed.

Abstract

The AdS3/CFT2 correspondence features massless non-relativistic modes on the string worldsheet in lightcone gauge. We study in detail these excitations and highlight how they naturally split between chiral (left-moving) and anti-chiral (right-moving) representations. In light of this split we discuss the constraints on the two-particle worldsheet S matrix imposed by braiding and physical unitarity, parity, time-reversal, and crossing invariance. We also comment on the implication of this split in the mirror kinematics.