The pinch technique approach to gauge-independent n-point functions

Abstract

The pinch technique (PT) is an algorithm for the rearrangement of contributions to conventional, gauge-dependent n-point functions in gauge theories to obtain a formulation of one-loop perturbation theory in terms of ``effective'' n-point functions which, principle among many other desirable properties, are individually entirely independent of the particular gauge-fixing procedure used. The aim of this talk is to give an introductory account of (i) the phenomenological motivations for the PT approach, (ii) the PT algorithm, including the principle properties of the PT n-point functions, (iii) an example application, and (iv) recent progress in extending the PT beyond the one-loop level.