Dominance of extreme statistics in a prototype many-body Brownian ratchet

TL;DR

This paper investigates how correlations among filaments in a many-body Brownian ratchet influence its steady-state behavior, revealing that extreme fluctuations dominate the system's dynamics and significantly affect the gel's density near the leading edge.

Contribution

It introduces a self-consistent theoretical framework to quantify the impact of extreme fluctuations in filament distributions within a many-body Brownian ratchet.

Findings

Correlations among filaments significantly affect steady-state kinetics.

Extreme fluctuations deplete the gel density near the leading edge.

A self-consistent theory accurately captures these fluctuation effects.

Abstract

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.