LIGHT-LIKE INTEGRABILITY IN LOOP SUPERSPACE, KAC MOODY CENTRAL CHARGES AND CHERN SIMONS TERMS

We apply the idea of light-like integrability in loop superspace to give a complete derivation of all the constraints of on-shell ten-dimensional supergravity coupled to Yang-Mills. The Yang-Mills Chern-Simons coupling terms are obtained by adding a central extension to the Kac-Moody algebra of the Yang-Mills generators. The form of the loop-superspace covariant derivatives, including the central charge modifications, can also be derived by means of canonical quantization from a Green-Schwarz super-string coupled to a supergravity and super-Yang-Mills background. There the Yang-Mills sector is represented by bosonic group coordinates, which are chiral and describe a gauged Wess-Zumino-Witten model.