Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-energy cosmic ray production by a neutron star falling into a black
  hole   We propose a one-shot mechanism for high-energy cosmic ray generation by a
neutron star falling into a black hole surrounded by low density plasma. The
function of the black hole in this scenario is to accelerate the star to a
speed arbitrarily close to that of light. When the star - essentially, a
magnetized sphere - approaches the horizon it imparts energy to the ambient
plasma charges via the induced electric field. Disregarding radiation losses,
for iron nucleus, a simple estimate gives energies on the order of 10^19 eV for
stars with magnetic fields as weak as 10^6 teslas. The proposed mechanism
should also work in chance encounters between rapidly moving neutron stars and
molecular clouds. The rarity of such encounters may explain the apparent
randomness and rarity of the high-energy cosmic ray events.

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The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas