  We map self-avoiding random walks with a chemical potential for writhe to the
three-dimensional complex O(N) Chern-Simons theory as N -> 0. We argue that at
the Wilson-Fisher fixed point which characterizes normal self-avoiding walks
(with radius of gyration exponent nu = 0.588) a small chemical potential for
writhe is irrelevant and the Chern-Simons field does not modify the monomer-
monomer correlation function. For a large chemical potential the polymer
collapses.
