Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constraints on primordial black holes and primeval density perturbations
  from the epoch of reionization   We investigate the constraint on the abundance of primordial black holes
(PBHs) and the spectral index $n$ of primeval density perturbations given by
the ionizing photon background at the epoch of reionization. Within the
standard inflationary cosmogony, we show that the spectral index $n$ of the
power-law power spectrum of primeval density perturbations should be $n<$1.27.
Since the universe is still optical thick at the reionization redshift $z\sim
6$ - 8, this constraint is independent of the unknown parameter of reheating
temperature of the inflation. The ionizing photon background from the PBHs can
be well approximated by a power law spectrum $J(\nu)\propto{\nu}^3$, which is
greatly different from those given by models of massive stars and quasars.

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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys