Q -Poincaré invariance of the AdS3 /CFT2 R -matrix

Abstract

We consider the exact R-matrix of AdS3/CFT2, which is the building block for describing the scattering of worldsheet excitations of the light-cone gauge-fixed backgrounds AdS3×S3×T4 and AdS3×S3×S3×S1 with pure Ramond-Ramond fluxes. We show that R is invariant under a "deformed boost" symmetry, for which we write an explicit exact coproduct, i.e. its action on two-particle states. When we include the boost, the symmetries of the R-matrix close into a q-Poincaré superalgebra. Our findings suggest that the recently discovered boost invariance in AdS5/CFT4 may be a common feature of AdS/CFT systems that are treatable with the exact techniques of integrability. With the aim of going towards a universal formulation of the underlying Hopf algebra, we also propose a universal form of the AdS3/CFT2 classical r-matrix.