  We study the low temperature dynamics of the classical Heisenberg
antiferromagnet with nearest neighbour interactions on the pyrochlore lattice.
We present extensive results for the wavevector and frequency dependence of the
dynamical structure factor, obtained from simulations of the precessional
dynamics. We also construct a solvable stochastic model for dynamics with
conserved magnetisation, which accurately reproduces most features of the
precessional results. Spin correlations relax at a rate independent of
wavevector and proportional to temperature.
