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 constrained system on the group
G, we show that these inequivalent quantizations can be recovered from a
generalization of Dirac's approach to the quantization of such a constrained
system within which the classical first class constraints (generating the
H-action on G) are allowed to become anomalous (second class) when quantizing.
The resulting quantum theories are characterized by the emergence of a
Yang-Mills connection, with quantized couplings, and new 'spin' degrees of
{}freedom. Various applications of this procedure are presented in detail:
including a new account of how spin can be described within a path-integral
formalism, and how on S^4 chiral spin degrees of {}freedom emerge, coupled to a
BPST instanton.Comment: 64 pages, plain TeX, DIAS-STP-93-1