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Learning entropy production from underdamped Langevin trajectories
Jinghao Lyu1, Kyle J Ray1, James P Crutchfield1
1University of California at Davis, Complexity Sciences Center and Physics and Astronomy Department, One Shields Avenue, Davis, California 95616, USA.
Physical Review. E
|February 7, 2025
Summary
Researchers developed a new method using modified thermodynamic uncertainty relations to estimate entropy production in complex physical systems. This approach works for both overdamped and underdamped Langevin dynamics, offering broader applicability.
Area of Science:
- Physics
- Physical Chemistry
- Statistical Mechanics
Background:
- Entropy production (EP) quantifies energy dissipation and irreversibility in nonequilibrium systems.
- Estimating EP is difficult due to limited knowledge of system dynamics.
- Existing methods using thermodynamic uncertainty relations (TURs) are limited to overdamped systems.
Purpose of the Study:
- To develop a novel method for estimating entropy production in underdamped Langevin systems.
- To extend the application of thermodynamic uncertainty relations (TURs) to a wider range of physical systems.
- To provide a flexible approach for calculating EP with limited dynamic information.
Main Methods:
- Derivation of a modified TUR relating cumulant and stochastic currents to EP.
- Utilizing a family of currents that allows for saturation of uncertainty relations.
- Requiring only knowledge of the damping coefficient to mass ratio and diffusion constant.
Main Results:
- A modified TUR is established for estimating EP in both overdamped and underdamped Langevin dynamics.
- The method is validated numerically on various underdamped systems.
- The derived uncertainty relations can saturate even for long-time averages and non-steady-state conditions.
Conclusions:
- The novel modified TUR provides a flexible and broadly applicable method for estimating entropy production.
- This advancement overcomes limitations of previous methods, enabling EP estimation in underdamped systems.
- The findings contribute to a deeper understanding of energy dissipation and irreversibility in nonequilibrium physics.
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