RESOLUTION OF GAUSS LAW IN YANG-MILLS THEORY BY GAUGE-INVARIANT PROJECTION - TOPOLOGY AND MAGNETIC MONOPOLES

An efficient way of resolving Gauss' law in Yang-Mills theory is prese nted by starting from the projected gauge-invariant partition function and integrating out one spatial field variable. In this way one obtai ns immediately the description in terms of unconstrained gauge-invaria nt variables which was previously obtained by explicitly reserving Gau ss' law in a modified axial gauge. In this gauge, which is a Variant o f't Hooft's Abelian gauges, magnetic monopoles occur. It is shown how the Pontryagin index of the gauge field is related to the magnetic cha rges. It turns out that the magnetic monopoles are sufficient to accou nt for the non-trivial topological structure of the theory. (C) 1997 E lsevier Science B.V.