In this paper we investigate the form of induced gauge fields that arises in two types of quantum systems. In the first we consider quantum mechanics on coset spaces G/H, and argue that G-invarianceâ€¦ (More)

Recent progress in the construction of both electric, coloured and magnetic charges in gauge theories will be presented. The topological properties of the charged sectors will be highlighted as wellâ€¦ (More)

We investigate the properties of a dressed electron which reduces, in a particular class of gauges, to the usual fermion. A one loop calculation of the propagator is presented. We show explicitlyâ€¦ (More)

Starting from the observation that colour charge is only well defined on gauge invariant states, we construct perturbatively gauge invariant, dynamical dressings for individual quarks. Explicitâ€¦ (More)

It has been known for some time that there are many inequivalent quantizations possible when the configuration space of a system is a coset space G/H. Viewing this classical system as a constrainedâ€¦ (More)

Gauge theories are characterised by long range interactions. Neglecting these interactions at large times, and identifying the Lagrangian matter fields with the asymptotic physical fields, leads toâ€¦ (More)

There is a widespread belief in particle physics that there is no relativistic description of a charged particle. This is claimed to be due to persistent, long range interactions which distort the inâ€¦ (More)

BRST invariance supplies a sufficient condition for the observability of fields. We show that there is a global obstruction to the observability of quarks and gluons and argue that they will notâ€¦ (More)

A crucial element of scattering theory and the LSZ reduction formula is the assumption that the coupling vanishes at large times. This is known not to hold for the theories of the Standard Model andâ€¦ (More)

The quarks of quark models cannot be identi ed with the quarks of the QCD Lagrangian. We review the restrictions that gauge eld theories place on any description of physical (colour) charges. Aâ€¦ (More)