Fluctuations in the Ensemble of Reaction Pathways

TL;DR

This paper develops a method to incorporate stochastic fluctuations around dominant reaction pathways at various temperatures, improving the accuracy of transition probabilities and reaction rates in non-equilibrium systems.

Contribution

It introduces a systematic technique to include thermal fluctuations in the dominant reaction pathway framework, enhancing its applicability at higher temperatures.

Findings

Method accurately predicts transition probabilities.

Reaction rate calculations are improved by including fluctuations.

Applicable across different temperature regimes.

Abstract

The dominant reaction pathway (DRP) is a rigorous framework to microscopically compute the most probable trajectories, in non-equilibrium transitions. In the low-temperature regime, such dominant pathways encode the information about the reaction mechanism and can be used to estimate non-equilibrium averages of arbitrary observables. On the other hand, at sufficiently high temperatures, the stochastic fluctuations around the dominant paths become important and have to be taken into account. In this work, we develop a technique to systematically include the effects of such stochastic fluctuations, to order k_B T. This method is used to compute the probability for a transition to take place through a specific reaction channel and to evaluate the reaction rate.