Worldsheet scattering in AdS(3)/CFT(2)

Understand

We confront the recently proposed exact S-matrices for AdS(3)/CFT(2) with direct worldsheet calculations.

• Utilizing the BMN and Near Flat Space (NFS) expansions for strings on AdS(3) x S(3) x S(3) x S(1) and AdS(3) x S(3) x T(4) we compute both tree-level and one-loop scattering amplitudes.
• Up to some minor issues we find nice agreement in the tree-level sector.
• At the one-loop level however we find that certain non-zero tree-level processes, which are not visible in the exact solution, contribute, via the optical theorem, and give an apparent mismatch for certain amplitudes.