  The Rubinstein-Duke or repton model is one of the simplest lattice model of
reptation for the diffusion of a polymer in a gel or a melt. Recently, a
slightly modified model with hardcore interactions between the reptons has been
introduced. The curvilinear diffusion coefficients of both models are exactly
determined for all chain lengths. The case of periodic boundary conditions is
also considered.

Soft Condensed Matter;Statistical Mechanics