Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particle Acceleration in Kerr-(anti-) de Sitter Black Hole Backgrounds   Recently, Ban\~{a}dos, Silk and West (BSW) found that the center-of-mass
energy of two colliding test particles in the neighborhood of an extreme Kerr
black hole could be arbitrarily high when one particle has the critical angular
momentum $L_\text{C}$. In their paper, they considered the black holes living
in a Minkowski space-time with a zero cosmological constant. In this work, we
study this process of particles in the backgrounds of the Kerr black holes
living in a space-time with a nonzero cosmological constant. We find that for
kerr black holes living in a space-time with a negative cosmological constant
(Kerr-anti-de Sitter black holes), this process of particles could happen only
if the Kerr-anti-de Sitter black hole is extreme and an additional fine tuning
is satisfied; while for kerr black holes living in a space-time with a positive
cosmological constant (Kerr-de Sitter black holes), this process of particles
could happen no matter the Kerr-de Sitter black hole is extreme or not. We also
study the particle collision outside the outer horizon of the Kerr-(anti-) de
Sitter black hole in some cases. We find that there is a possibility that we
could tune one colliding particle's angular momentum to gain the large
center-of-mass energy without increase the particle's energy.

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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: adap-org
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th