DIFFUSION OF A SELF-AVOIDING POLYMER

We study the diffusion of a polymer where we take into account self-avoidance. We introduce a reptation model in which the diffusion of stored length is infinitely rapid. For this model, we find that the diffusion coefficient scales with the length of the polymer as N-2 nu-2, where nu is the self-avoiding walk exponent for N ranging over almost two orders of magnitude. This result is used to argue that for physical polymers the diffusion coefficient is proportional to N-2 nu-3 when self-avoidance is significant.