A model for the dynamics of extensible semiflexible polymers

We present a model for semiflexible polymers in a Hamiltonian formulation that interpolates between a Rouse chain and a worm-like chain. Both models are realized as limits for the parameters. The model parameters can also be chosen to match the experimental force-extension curve for double-stranded DNA. Near the ground state of the Hamiltonian, the eigenvalues for the longitudinal (stretching) and transverse (bending) modes of a chain with N springs, indexed by p, scale as lambda(l)(p) similar to (p/N)(2) and lambda(t)(p) similar to p(2)(p-1)(2)/N-4 respectively for small p. We also show that the associated decay times tau(p) similar to (N/p)(4) will not be observed if they exceed the orientational time scale tau(r) similar to N-3 for an equally long rigid rod, as the driven decay is then washed out by diffusive motion.