MAGNETIC MONOPOLES, GAUGE-INVARIANT DYNAMICAL VARIABLES AND GEORGI-GLASHOW MODEL

We investigate the Georgi-Glashow model in terms of a set of explicitl y SO(3) gauge invariant dynamical variables. In the new description a novel compact abelian gauge invariance emerges naturally which is not a subgroup of the original gauge group. The magnetic monopoles occur a s point-like ''defects'' in spacetime and couple to the abelian gauge field with coupling (1/e). Their non-perturbative contribution to the partition function is made explicit. This procedure corresponds to dyn amical ''abelian projection'' without gauge fixing. The effect of the theta term in the abelian version of the theory is also studied. (C) 1 997 Published by Elsevier Science B.V.