  We develop a topological method of measuring Chern-Simons number change in
the real time evolution of classical lattice SU(2) and SU(2) Higgs theory. We
find that the Chern-Simons number diffusion rate per physical 4-volume is very
heavily suppressed in the broken phase, and that it decreases with lattice
spacing in pure Yang-Mills theory, although not as quickly as predicted by
Arnold, Son, and Yaffe.
