Comments on Superstring Interactions in a Plane-Wave Background
  The three string vertex for Type IIB superstrings in a maximally supersymmetric plane-wave background is investigated. Specifically, we derive a factorization theorem for the Neumann coefficients that generalizes a flat-space result that was obtained some 20 years ago. The resulting formula is used to explore the leading large mu asymptotic behavior, which is relevant for comparison with dual gauge theory results. 
John H. Schwarz