Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CMB Constraint on Dark Matter Annihilation after Planck 2015   We update the constraint on the dark matter annihilation cross section by
using the recent measurements of the CMB anisotropy by the Planck satellite. We
fully calculate the cascade of dark matter annihilation products and their
effects on ionization, heating and excitation of the hydrogen, hence do not
rely on any assumption on the energy fractions that cause these effects.

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The categories of this paper are: cond-mat
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The categories of this paper are: plasm-ph
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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: dg-ga
32
The categories of this paper are: atom-ph
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The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
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The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: nlin
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn