Magnetic monopoles, gauge invariant dynamical variables and Georgi-Glashow model

We investigate the Georgi-Glashow model in terms of a set of explicitly 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 as 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 dynamical ''abelian projection'' without gauge fixing. The effect of the theta term in the abelian version of the theory is also studied. (C) 1997 Published by Elsevier Science B.V.