All-loop Bethe ansatz equations for AdS3/CFT2

Understand

Using the S-matrix for the d(2,1;alpha)^2 symmetric spin-chain of AdS3/CFT2, we propose a new set of all-loop Bethe equations for the system.

• These equations differ from the ones previously found in the literature by the choice of relative grading between the two copies of the d(2,1;alpha) superalgebra, and involve four undetermined scalar factors that play the role of dressing phases.
• Imposing crossing symmetry and comparing with the near-BMN form of the S-matrix found in the literature, we find several novel features.
• In particular, the scalar factors must differ from the Beisert-Eden-Staudacher phase, and should couple nodes of different masses to each other.