Séminaire de groupe
|Unwinding relaxation dynamics of polymers|
|jeudi 04 avril 2013 , 10h25|
|Salle de séminaire du groupe de Physique Statistique|
The relaxation dynamics of a polymer wound around a fixed obstacle constitutes a fundamental instance of polymer with twist and torque and it is of relevance also for DNA denaturation dynamics. After an introduction on polymer physics and static properties of the winding of a polymer, we present our investigations of the unwinding dynamics by means of simulations and Langevin equation analysis. The latter predicts a relaxation time scaling as a power of the polymer length times a logarithmic correction related to the equilibrium fluctuations of the winding angle. The numerical data support this result and show that at short times the winding angle decreases as a power-law. This is also in agreement with the Langevin equation provided a winding-dependent friction is used, suggesting that such reduced description of the system captures the basic features of the problem.