Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonequilibrium Casimir pressures in liquids under shear   In stationary nonequilibrium states coupling between hydrodynamic modes
causes thermal fluctuations to become long ranged inducing nonequilibrium
Casimir pressures. Here we consider nonequilibrium Casimir pressures induced in
liquids by a velocity gradient. Specifically, we have obtained explicit
expressions for the magnitude of the shear-induced pressure enhancements in a
liquid layer between two horizontal plates that complete and correct results
previously presented in the literature. In contrast to nonequilibrium Casimir
pressures induced by a temperature or concentration gradient, we find that in
shear nonequilibrium contributions from short-range fluctuations are no longer
negligible. In addition, it is noted that currently available computer
simulations of model fluids in shear observe effects from molecular
correlations at nanoscales that have a different physical origin and do not
probe shear-induced pressures resulting from coupling of long-wavelength
hydrodynamic modes. Even more importantly, we find that in actual experimental
conditions, shear-induced pressure enhancements are caused by viscous heating
and not by thermal velocity fluctuations. Hence, isothermal computer
simulations are irrelevant for the interpretation of experimental shear-induced
pressure enhancements.

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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph