Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Applicability of the Newman-Janis Algorithm to Black Hole Solutions of
  Modified Gravity Theories   The Newman-Janis algorithm has been widely used to construct rotating black
hole solutions from non-rotating counterparts. While this algorithm was
developed within General Relativity, it has more recently been applied to
non-rotating solutions in modified gravity theories. We find that the
application of the Newman-Janis algorithm to an arbitrary non-GR
spherically-symmetric solution introduces pathologies in the resulting
axially-symmetric metric. This then establishes that, in general, the
Newman-Janis algorithm should not used to construct rotating black hole
solutions outside of General Relativity.

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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: physics
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin