The complete AdS_3 x S^3 x T^4 worldsheet S-matrix

TL;DR

This paper derives the exact worldsheet S-matrix for Type IIB superstring theory on AdS_3 x S^3 x T^4, including massless modes, advancing the understanding of integrability in AdS_3/CFT_2 correspondence.

Contribution

It provides the non-perturbative S matrix for AdS_3 x S^3 x T^4, including massless excitations, and derives crossing equations for scalar factors, addressing previous limitations.

Findings

Derived the full non-perturbative S matrix including massless modes

Established crossing equations for scalar factors in the S matrix

Included off-shell symmetry algebra in the analysis

Abstract

We derive the non-perturbative worldsheet S matrix for fundamental excitations of Type IIB superstring theory on AdS_3 x S^3 x T^4 with Ramond-Ramond flux. To this end, we study the off-shell symmetry algebra of the theory and its representations. We use these to determine the S matrix up to scalar factors and we derive the crossing equations that these scalar factors satisfy. Our treatment automatically includes fundamental massless excitations, removing a long-standing obstacle in using integrability to study the AdS_3/CFT_2 correspondence. The present paper contains a detailed derivation of results first announced in arXiv:1403.4543.