Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Higher Conservation Law for the Multi-Centre Metrics   The multi-centre metrics are a family of euclidean solutions of the empty
space Einstein equations with self-dual curvature. For this full class, we
determine which metrics do exhibit an extra conserved quantity quadraic in the
momenta, induced by a Killing-Stackel tensor. Our results bring to light
several metrics which correspond to classically integrable dynamical systems.
They include, as particular cases, the Eguchi-Hanson and Taub-NUT metrics.

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The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
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The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: dg-ga
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The categories of this paper are: math