Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singularities in the acoustic Casimir pressure as a function of
  reflectivities   We study the acoustic Casimir pressure between imperfectly reflecting plates
immersed in various isotropic noise backgrounds. Unlike the case of perfect
reflectors, the force tends to strong repulsion at small plate separations due
to the existence of modes between the plates. Additionally, in a noise field of
constant spectral intensity, the large-bandwidth limit of the pressure has a
reflectivity-dependent sensitivity to the infrared cutoff; we uncover the
associated singular behavior as the product of the reflection coefficients
approaches 1, which is intimately connected to a tendency of closely-spaced
plates to repel if placed in a narrowly peaked spectral background.

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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat