Dominance of extreme statistics in a prototype many-body Brownian   ratchet
  Many forms of cell motility rely on Brownian ratchet mechanisms that involve multiple stochastic processes. We present a computational and theoretical study of the nonequilibrium statistical dynamics of such a many-body ratchet, in the specific form of a growing polymer gel that pushes a diffusing obstacle. We find that oft-neglected correlations among constituent filaments impact steady-state kinetics and significantly deplete the gel's density within molecular distances of its leading edge. These behaviors are captured quantitatively by a self-consistent theory for extreme fluctuations in filaments' spatial distribution. 
Evan Hohlfeld and Phillip L. Geissler
cond-mat.stat-mech cond-mat.soft physics.bio-ph q-bio.SC