Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tri-Hamiltonian Structures of The Egorov Systems   The description of the Egorov hydrodynamic type systems is presented in
language of conservation laws. Under extra conditions of semisimplicity and
homogeneity tri-Hamiltonian structures of such systems are described. Even and
odd cases are related with flat and metric of constant curvature, respectively.
Some important and well-known examples like averaged by Whitham approach and
dispersionless limits of vector NLS and vector LSR are investigated.

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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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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: adap-org
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The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
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The categories of this paper are: plasm-ph