Crossover from reptation to Rouse dynamics in a one-dimensional model
  A simple one-dimensional model is constructed for polymer motion. It exhibits the crossover from reptation to Rouse dynamics through gradually allowing hernia creation and annihilation. The model is treated by the density matrix technique which permits an accurate finite-size-scaling analysis of the behavior of long polymers. 
Andrzej Drzewinski, J. M. J. van Leeuwen