Flow and structure in nonequilibrium Brownian many-body systems

TL;DR

This paper introduces a classification of forces in nonequilibrium Brownian many-body systems under flow, providing a power functional theory to quantify these forces and their effects on structure and motion.

Contribution

It offers a systematic split of internal forces into structure- and motion-relevant parts and presents a power functional framework applicable to inertial systems.

Findings

Both force contributions can be obtained in simulations

The power functional theory describes all force types quantitatively

Applicable to molecular liquids and granular media

Abstract

We present a fundamental classification of forces relevant in nonequilibrium structure formation under collective flow in Brownian many-body systems. The internal one-body force field is systematically split into contributions relevant for the spatial structure and for the coupled motion. We demonstrate that both contributions can be obtained straightforwardly in computer simulations, and present a power functional theory that describes all types of forces quantitatively. Our conclusions and methods are relevant for flow in inertial systems, such as molecular liquids and granular media.