Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Horizon crossing causes baryogenesis, magnetogenesis and dark-matter
  acoustic wave   Sapcetime ${\mathcal S}$ produces massive particle-antiparticle pairs $\bar F
F$ that in turn annihilate to spacetime. Such back and forth gravitational
process ${\mathcal S}\Leftrightarrow \bar F F$ is described by Boltzmann-type
cosmic rate equation of pair-number conservation. This cosmic rate equation,
Einstein equation, and the reheating equation of pairs decay to relativistic
particles completely determine the horizon $H$, cosmological energy density,
massive pair and radiation energy densities in reheating epoch. Moreover,
oscillating ${\mathcal S}\Leftrightarrow \bar F F$ process leads to the
acoustic perturbations of massive particle-antiparticle symmetric and
asymmetric densities. We derive wave equations for these perturbations and find
frequencies of lowest lying modes. Comparing their wavelengths with horizon
variation, we show their subhorion crossing at preheating, and superhorizon
crossing at reheating. The superhorizon crossing of particle-antiparticle
asymmetric perturbations accounts for the baryogenesis of net baryon numbers,
whose electric currents lead to magnetogenesis. The baryon number-to-entropy
ratio, upper and lower limits of primeval magnetic fields are computed in
accordance with observations. Given a pivot comoving wavelength, it is shown
that these perturbations, as dark-matter acoustic waves, originate in
pre-inflation and return back to the horizon after the recombination, possibly
leaving imprints on the matter power spectrum at large length scales. Due to
the Jeans instability, tiny pair-density acoustic perturbations in superhorizon
can be amplified to the order of unity. Thus their amplitudes at reentry
horizon become non-linear and maintain approximately constant physical sizes,
and have physical influences on the formation of large scale structure and
galaxies.

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The categories of this paper are: math
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: physics