Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Numerical investigation of plasma-driven superradiant instabilities   Photons propagating in a plasma acquire an effective mass $\mu$, which is
given by the plasma frequency and which scales with the square root of the
plasma density. As noted previously by Conlon and Herdeiro, for electron number
densities $n_e\sim 10^{-3}$ cm$^{-3}$ (such as those measured in the
interstellar medium) the effective mass induced by the plasma is $\mu \sim
10^{-12}$ eV. This would cause superradiant instabilities for spinning black
holes of a few tens of solar masses. An obvious problem with this picture is
that densities in the vicinity of black holes are much higher than in the
interstellar medium because of accretion. We have conducted numerical
simulations of the superradiant instability in spinning black holes surrounded
by a plasma with density increasing closer to the black hole, in order to mimic
the effect of accretion. While we confirm that superradiant instabilities
appear for plasma densities that are sufficiently low near the black hole, we
find that astrophysically realistic accretion disks are unlikely to trigger
such instabilities.

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The categories of this paper are: q-alg
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
2
The categories of this paper are: math
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: physics
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The categories of this paper are: math-ph