Brownian motion of the wormlike chain and segmental diffusion of DNA

Abstract

The dynamics of the wormlike chain model for a polymer in solution is investigated in the case of free torsional and no longitudinal variations. A Langevin equation is derived and solved for circularly closed chains, neglecting hydrodynamic interactions. The local diffusion behavior of particular segments is described, and it is found that the mean‐square displacements are proportional to t^3/4 at short times. Also, the equilibrium correlation functions for the closed chain are derived from the dynamic model in both the discrete and wormlike cases.