Statistics of Infima and Stopping Times of Entropy Production and Applications to Active Molecular Processes

TL;DR

This paper investigates the universal statistical properties of entropy production in nonequilibrium steady states, deriving exact distributions and fluctuation theorems for infima and stopping times, with applications to molecular motors and active processes.

Contribution

It provides the first exact expressions for entropy production passage probabilities and establishes a fluctuation theorem for stopping-time distributions, revealing universal features.

Findings

The global infimum of entropy production follows an exponential distribution with mean minus Boltzmann's constant.

Exact formulas for entropy production reaching a specific value are derived.

A fluctuation theorem for stopping-time distributions of entropy production is established.

Abstract

We study the statistics of infima, stopping times and passage probabilities of entropy production in nonequilibrium steady states, and show that they are universal. We consider two examples of stopping times: first-passage times of entropy production and waiting times of stochastic processes, which are the times when a system reaches for the first time a given state. Our main results are: (i) the distribution of the global infimum of entropy production is exponential with mean equal to minus Boltzmann's constant; (ii) we find the exact expressions for the passage probabilities of entropy production to reach a given value; (iii) we derive a fluctuation theorem for stopping-time distributions of entropy production. These results have interesting implications for stochastic processes that can be discussed in simple colloidal systems and in active molecular processes. In particular, we show that the timing and statistics of discrete chemical transitions of molecular processes, such as, the steps of molecular motors, are governed by the statistics of entropy production. We also show that the extreme-value statistics of active molecular processes are governed by entropy production, for example, the infimum of entropy production of a motor can be related to the maximal excursion of a motor against the direction of an external force. Using this relation, we make predictions for the distribution of the maximum backtrack depth of RNA polymerases, which follows from our universal results for entropy-production infima.