Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spinor Fields and Symmetries of the Spacetime   In the background of a stationary black hole, the "conserved current" of a
particular spinor field always approaches the null Killing vector on the
horizon. What's more, when the black hole is asymptotically flat and when the
coordinate system is asymptotically static, then the same current also
approaches the time Killing vector at the spatial infinity. We test these
results against various black hole solutions and no exception is found. The
spinor field only needs to satisfy a very general and simple constraint.

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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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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: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: atom-ph