Reptation of star polymers in a network: Monte Carlo results of diffusion coefficients

We report on Monte Carlo results of diffusion coefficients of lattice star polymers trapped inside a fixed network (de Gennes model). It is found that our data are in agreement with the Helfand-Pearson exponential factor alpha = 0.29. For the preexponential power law exponent we find beta = 2. In contrast to existing theoretical predictions, we find that the number of arms f leads to a preexponential factor of the form exp(-0.75f).