Key points are not available for this paper at this time.
The effective gauge field action due to an odd number of fermion species in three-dimensional SU (N) gauge theories is shown to change by |n| under a homotopically nontrivial gauge transformation with winding number n. Gauge invariance can be restored by use of Pauli-Villars regularization, which, however, introduces parity nonconservation in the form of a parity-nonconserving, topological term in the effective action.
Amanda Redlich (Mon,) studied this question.