Thermodynamic uncertainty relation for Langevin dynamics by scaling time

TL;DR

This paper introduces a unified large deviation theory approach to derive thermodynamic uncertainty relations for both overdamped and underdamped Langevin dynamics by scaling time, providing new insights into current fluctuation bounds.

Contribution

It offers a novel, unified large deviation framework for TUR bounds applicable to both overdamped and underdamped Langevin systems, expanding beyond previous information-theoretic methods.

Findings

Derived TUR-like bounds for Langevin dynamics using large deviation theory.

Unified treatment applicable to both overdamped and underdamped cases.

Results are similar to known bounds but with new rationalizations.

Abstract

The thermodynamic uncertainty relation (TUR) quantifies a relationship between current fluctuations and dissipation in out-of-equilibrium overdamped Langevin dynamics, making it a natural counterpart of the fluctuation-dissipation theorem in equilibrium statistical mechanics. For underdamped Langevin dynamics, the situation is known to be more complicated, with dynamical activity also playing a role in limiting the magnitude of current fluctuations. Progress on those underdamped TUR-like bounds has largely come from applications of the information-theoretic Cram\'er-Rao inequality. Here, we present an alternative perspective by employing large deviation theory. The approach offers a general, unified treatment of TUR-like bounds for both overdamped and underdamped Langevin dynamics built upon current fluctuations achieved by scaling time. The bounds we derive following this approach are similar to known results but with differences we discuss and rationalize.