  A parametrization of gauge fields on complex projective spaces of arbitrary
dimension is given as a generalization of the two-dimensional case. Gauge
transformations act homogeneously on the fields, facilitating a manifestly
gauge-invariant analysis. Specializing to four dimensions, we consider the
nature of the effective action due to chiral scalars interacting with the gauge
fields. The key qualitatively significant terms include a possible
gauge-invariant mass term and a finite four-dimensional Wess-Zumino-Witten
(WZW) action. We comment on relating the mass term to lattice simulations as
well as Schwinger-Dyson analyses, and also on relating the WZW action to the
instanton liquid picture of QCD.
