The gauss law: A tale

Abstract

The Gauss law plays a basic role in gauge theories, enforcing gauge invariance and creating edge states and superselection sectors. This article surveys these aspects of the Gauss law in QED, QCD and nonlinear G/H models. It is argued that nonabelian superselection rules are spontaneously broken. That is the case with SU(3) of colour which is spontaneously broken to U(1) × U(1). Nonlinear G/H models are reformulated as gauge theories and the existence of edge states and superselection sectors in these models is also established.