Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Kerr-Newman metric: A Review   The Kerr-Newman metric describes a very special rotating, charged mass and is
the most general of the asymptotically flat stationary 'black hole' solutions
to the Einstein-Maxwell equations of general relativity. We review the
derivation of this metric from the Reissner-Nordstrom solution by means of a
complex transformation algorithm and provide a brief overview of its basic
geometric properties. We also include some discussion of interpretive issues,
related metrics, and higher-dimensional analogues.

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The categories of this paper are: nucl-th
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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci