Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cold Plasma Dispersion Relations in the Vicinity of a Schwarzschild
  Black Hole Horizon   We apply the ADM 3+1 formalism to derive the general relativistic
magnetohydrodynamic equations for cold plasma in spatially flat Schwarzschild
metric. Respective perturbed equations are linearized for non-magnetized and
magnetized plasmas both in non-rotating and rotating backgrounds. These are
then Fourier analyzed and the corresponding dispersion relations are obtained.
These relations are discussed for the existence of waves with positive angular
frequency in the region near the horizon. Our results support the fact that no
information can be extracted from the Schwarzschild black hole. It is concluded
that negative phase velocity propagates in the rotating background whether the
black hole is rotating or non-rotating.

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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
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The categories of this paper are: hep-th
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: cs
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The categories of this paper are: alg-geom
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The categories of this paper are: eess
15
The categories of this paper are: nucl-ex