Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extremal Kerr-Newman black holes with extremely short charged scalar
  hair   The recently proved `no short hair' theorem asserts that, if a
spherically-symmetric static black hole has hair, then this hair (the external
fields) must extend beyond the null circular geodesic (the "photonsphere") of
the corresponding black-hole spacetime: $r_{\text{field}}>r_{\text{null}}$. In
this paper we provide compelling evidence that the bound can be {\it violated}
by {\it non}-spherically symmetric hairy black-hole configurations. To that
end, we analytically explore the physical properties of cloudy Kerr-Newman
black-hole spacetimes -- charged rotating black holes which support linearized
stationary charged scalar configurations in their exterior regions.

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The categories of this paper are: math
26
The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
1
The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex