Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhancement of Diffusive Transport by Nonequilibrium Thermal
  Fluctuations   We study the contribution of advection by thermal velocity fluctuations to
the effective diffusion coefficient in a mixture of two identical fluids. The
steady-state diffusive flux in a finite system subject to a concentration
gradient is enhanced because of long-range correlations between concentration
fluctuations and fluctuations of the velocity parallel to the concentration
gradient. The enhancement of the diffusive transport depends on the system size
L and grows as \ln(L/L_{0}) in quasi-two dimensional systems, while in three
dimensions it grows as L_{0}^{-1}-L^{-1}, where L_{0} is a reference length.
The predictions of a simple fluctuating hydrodynamics theory, closely related
to second-order mode-mode coupling analysis, are compared to results from
particle simulations and a finite-volume solver and excellent agreement is
observed. We elucidate the direct connection to the long-time tail of the
velocity autocorrelation function in finite systems, as well as finite-size
corrections employed in molecular dynamics calculations. Our results
conclusively demonstrate that the nonlinear advective terms need to be retained
in the equations of fluctuating hydrodynamics when modeling transport in
small-scale finite systems.

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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: q-bio
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The categories of this paper are: eess