  We study the rotational dynamics of a flexible polymer initially wrapped
around a rigid rod and unwinding from it. This dynamics is of interest in
several problems in biology and constitutes a fundamental instance of polymer
relaxation from a state of minimal entropy. We investigate the dynamics of
several quantities such as the total and local winding angles and metric
quantities. The results of simulations performed in two and three dimensions,
with and without self-avoidance, are explained by a theory based on scaling
arguments and on a balance between frictional and entropic forces. The early
stage of the dynamics is particularly rich, being characterized by three
coexisting phases.
