Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The general spin triangle   We consider the Heisenberg spin triangle with general coupling coefficients
and general spin quantum number $s$. The corresponding classical system is
completely integrable. In the quantum case the eigenvalue problem can be
reduced to that of tridiagonal matrices in at most $2s+1$ dimensions. The
corresponding energy spectrum exhibits what we will call spectral symmetries
due to the underlying permutational symmetry of the considered class of
Hamiltonians. As an application we explicitly calculate six classes of
universal polynomials that occur in the high temperature expansion of spin
triangles and more general spin systems. Aspects of quantum integrability are
also discussed in this context.

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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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The categories of this paper are: mtrl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org