Anomalous fluctuations of active polar filaments

TL;DR

This paper investigates the dynamic behavior of active polar filaments interacting with force-generating centers, revealing novel length-scale dependent rigidity and enhanced anomalous diffusion compared to passive filaments.

Contribution

It introduces a simple model capturing the fluctuating dynamics of active filaments, highlighting unexpected static and dynamic differences from passive filaments.

Findings

Filaments exhibit a novel length-scale dependent rigidity.

Active filaments show strongly enhanced anomalous diffusion.

Differences are significant when activity occurs on time-scales comparable to filament relaxation.

Abstract

Using a simple model, we study the fluctuating dynamics of inextensible, semiflexible polar filaments interacting with active and directed force generating centres such as molecular motors. Taking into account the fact that the activity occurs on time-scales comparable to the filament relaxation time, we obtain some unexpected differences between both the steady-state and dynamical behaviour of active as compared to passive filaments. For the statics, the filaments have a {novel} length-scale dependent rigidity. Dynamically, we find strongly enhanced anomalous diffusion.