We introduce a new model for the dynamics of a wormlike chain in an
environment that gives rise to a rough free energy landscape, which we baptise
the glassy wormlike chain. It is obtained from the common wormlike chain by an
exponential stretching of the relaxation spectrum of its long-wavelength
eigenmodes, controlled by a single stretching parameter. Predictions for
pertinent observables such as the dynamic structure factor and the
microrheological susceptibility exhibit the characteristics of soft glassy
rheology and compare favourably with experimental data for reconstituted
cytoskeletal networks and live cells. We speculate about the possible
microscopic origin of the stretching, implications for the nonlinear rheology,
and the potential physiological significance of our results.Comment: 12 pages, 8 figures. Minor correction