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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

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The covariant dissipation function for transient nonequilibrium states.

Denis J Evans¹, Debra J Searles, Stephen R Williams

¹Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory 0200, Australia.

The Journal of Chemical Physics

|August 17, 2010

Summary

This summary is machine-generated.

The covariant dissipation function, crucial in nonequilibrium statistical mechanics, relates simply to the initial dissipation function. Exact time-local fluctuation relations for deterministic systems do not exist, only asymptotic versions.

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Area of Science:

Statistical Mechanics
Physical Chemistry
Thermodynamics

Background:

The dissipation function is central to classical nonequilibrium statistical mechanics.
It underpins key theorems like the Evans-Searles fluctuation theorem.

Purpose of the Study:

To investigate how the dissipation function changes when defined with respect to a time-evolving distribution during relaxation.
To explore the relationship between this covariant dissipation function and the initial dissipation function.

Main Methods:

Theoretical analysis of the dissipation function in classical nonequilibrium statistical mechanics.
Mathematical derivation of relationships between different definitions of the dissipation function.

Main Results:

A simple, fixed relationship was found between the covariant dissipation function and the initial dissipation function.
Exact, time-local Evans-Searles fluctuation relations for deterministic systems were shown to be non-existent, with only asymptotic versions possible.

Conclusions:

The covariant dissipation function offers a simplified perspective on nonequilibrium statistical mechanics.
The findings clarify the limitations of exact fluctuation relations in deterministic systems.