Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Brillouin scattering and the CMB   Brillouin scattering of photons off the density fluctuations in a fluid is
potentially important for cosmology. We derive the Brillouin spectral
distortion of blackbody radiation, and discuss the possible implications for
the cosmic microwave background. The thermal Sunyaev-Zeldovich effect is
slightly modified by Brillouin distortion, but only at very long wavelengths.

33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
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The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an