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arXiv · 2506.16002

Unifying renormalized and bare viscosity in two-dimensional molecular dynamics simulations

Kazuma Yokota·Masato Itami·Shin-ichi Sasa
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Abstract

Fluctuating hydrodynamics provides a framework connecting mesoscopic fluctuations with macroscopic transport behavior. To bridge mesoscopic and macroscopic transport from microscopic dynamics, we introduce a wavenumber-dependent viscosity, defined via the equilibrium correlation of time-averaged Fourier components of the fine-grained shear stress field. Two-dimensional molecular dynamics simulations reveal its small-wavenumber divergence characteristic of the renormalized viscosity, while its large-wavenumber behavior determines the bare viscosity, thereby establishing a link between mesoscopic and macroscopic transport based on microscopic dynamics.

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Kazuma Yokota, Masato Itami, Shin-ichi Sasa. 2025-06-19. Unifying renormalized and bare viscosity in two-dimensional molecular dynamics simulations. https://doi.org/10.1103/58g1-c78g

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