Spin in kink-type field theories

This paper studies some classical three-dimensional field theories for which the ranges of the field variables are a 3-sphere, a 2-sphere, the symplectic group, Sp(n), the special orthogonal group, SO(3), and the Ssub(4,1) space of general relativistic metrics. The main result is the proof that these theories admit half-odd-integer spin, so that the 1-kink states are classical analogs of fermion states. (author)