Tube Concept for Entangled Stiff Fibers Predicts Their Dynamics in Space   and Time
  We study dynamically crowded solutions of stiff fibers deep in the semidilute regime, where the motion of a single constituent becomes increasingly confined to a narrow tube. The spatiotemporal dynamics for wave numbers resolving the motion in the confining tube becomes accessible in Brownian dynamics simulations upon employing a geometry-adapted neighbor list. We demonstrate that in such crowded environments the intermediate scattering function, characterizing the motion in space and time, can be predicted quantitatively by simulating a single freely diffusing phantom needle only, yet with very unusual diffusion coefficients. 
Sebastian Leitmann, Felix H\"ofling, and Thomas Franosch
cond-mat.soft cond-mat.stat-mech