Dynamic fluctuations of semiflexible filaments

We study both the longitudinal and transverse fluctuations of a semiflexibl e filament. Using scaling arguments and numerical simulations, we find seve ral regimes for the longitudinal fluctuations which, for shea times, scale as [delta r(parallel to)(2)] similar to t(7/8) and are correlated over a le ngth l(2) similar to t(1/8). Our results are pertinent to experiments on cr oss-linked filament systems and motor-filament assays. The techniques we de velop for the analysis of dynamic correlations should have wide application s in the study of polymer systems. [S0031-9007(99)09052-3].