Приближение сильной свяэи: ковариантное пертурбационное раэложение

Abstract

A covariant perturbation expansion is developed around Klauder’s independent-valued field theories as zeroth approximation. A diagram technique is constructed and an analytic regularization is introduced to handle the superficially divergent terms of the expansion. For a wide class of interactions, the divergent terms can be either compensated by renormalization or vanish identically after the removal of the regularization. As a result only tree diagrams are found to contribute to the various Green’s functions; nonetheless one finds nontrivial scattering amplitudes with correct clustering and positivity properties.