Gauge-invariant matter field actions from iterative N\"other coupling

Abstract

Generalizing Deser's work on pure $SU(2)$ gauge theory, we consider scalar, spinor and vector matter fields transforming under arbitrary representations of a non-Abelian, compact, semisimple internal Lie group which is a global symmetry of their actions. These matter fields are coupled to Abelian gauge fields through the process of iterative N\"other coupling. This procedure is shown to yield precisely the same locally gauge invariant theory (with the non-Abelian group as the gauge group) as obtained by the usual minimal coupling prescription originating from the Gauge Principle. Prospects of this non-geometrical formulation, towards better understanding of physical aspects of gauge theories, are briefly discussed.