On the perturbative formulation of quantum field theory with boundary

by Takács, Gábor

Abstract

I review work carried out with Z. Bajnok and G. Böhm (hep-th/0207079 + yet unpublished work). The LSZ reduction formalism for the case of QFT with a boundary is described, and used to prove the identity of two different definitions of the reflection matrix. The approach uses a novel formulation of perturbation theory with boundary, which is also convenient to investigate analytic properties of Feynman amplitudes, and is used to derive the Landau equations, Coleman-Norton interpretation and the Cutkosky rules. The application of the results is illustrated using boundary sine-Gordon theory.