Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CMB bounds on dark matter annihilation: Nucleon energy-losses after
  recombination   We consider the propagation and energy losses of protons and anti-protons
produced by dark matter annihilation at redshifts 100<z<~2000. In the case of
dark matter annihilations into quarks, gluons and weak gauge bosons, protons
and anti-protons carry about 20% of the energy injected into e^\pm and
\gamma's, but their interactions are normally neglected when deriving cosmic
microwave background bounds from altered recombination histories. Here, we
follow numerically the energy-loss history of typical protons/antiprotons in
the cosmological medium. We show that about half of their energy is channeled
into photons and e^\pm, and we present a simple prescription to estimate the
corresponding strengthening of the cosmic microwave background bounds on the
dark matter annihilation cross section.

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The categories of this paper are: cond-mat
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th