Boundary scattering in massless AdS3

Abstract

We study the boundary integrability problem of the massless sector of AdS3 × S3 × T4 string theory. Exploiting the difference-form of the massless scattering theory, we find a very simple and exhaustive list of reflection matrices for all the possible boundary coideal subalgebras — singlet and vector representations, right and left boundary — and check basic properties of our solutions, primarily the boundary Yang-Baxter equation, for all possible combinations of scattering particles.