Vacuum polarization and the geometric phase: Gauge invariance

Abstract

A nonperturbative approach to the vacuum polarization for quantized fermions in external vector potentials is discussed. It is shown that by a suitable choice of counterterms the vacuum polarization phase is both gauge and renormalization independent, within a large class of nonperturbative renormalizations.Comment: AmsTex file, 10 output pages, no figures. (Can be run with plain Tex, the file will call for the macros amstex.tex and amsppt.sty.