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arXiv · 2510.12557

Transport properties of stochastic fluids

Chandrodoy Chattopadhyay·Josh Ott·Thomas Schaefer·Vladimir V. Skokov
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Abstract

We study heat conduction and momentum transport in the context of stochastic fluid dynamics. We consider a fluid described by model H in the classification of Hohenberg and Halperin. We study both non-critical and critical fluids, and we investigate transport properties in two as well as three dimensions. Our results are based on numerical simulations of model H using a Metropolis algorithm, and we employ Kubo relations to extract transport coefficients. We observe the expected logarithmic divergence of the shear viscosity in a two-dimensional non-critical fluid. At a critical point, we find that the transport coefficients exhibit power-law scaling with the system size $L$. The strongest divergence is seen for the thermal conductivity $κ$ in two dimensions. We find $κ\sim L^{x_κ}$ with $x_κ=1.6\pm 0.1$. The divergence is weaker in three dimensions, $x_κ=1.25 \pm 0.3$, and the scaling exponent for the shear viscosity, $x_η$, is significantly smaller than $x_κ$ in both two and three dimensions.

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Chandrodoy Chattopadhyay, Josh Ott, Thomas Schaefer, Vladimir V. Skokov. 2025-12-02. Transport properties of stochastic fluids. https://arxiv.org/abs/2510.12557

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