CONSTRUCTION OF THE QUANTUM ACTION FOR PATH-INTEGRAL QUANTIZATION OF STRING FIELD-THEORY

A general method of constructing the quantum correction to the classical action for the path-integral quantization of SFT is presented. The basic principle is to keep both unitarity and BRS invariance which are violated in the naive quantization using the classical action alone. For this purpose we introduce a representation of the cutting equation in terms of Grassmann integrations. As an application the three-loop correction given in a previous paper is rederived quickly and confirmed to be a correct one. © 1990.