Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Q-operators for the open Heisenberg spin chain   We construct Q-operators for the open spin-1/2 XXX Heisenberg spin chain with
diagonal boundary matrices. The Q-operators are defined as traces over an
infinite-dimensional auxiliary space involving novel types of reflection
operators derived from the boundary Yang-Baxter equation. We argue that the
Q-operators defined in this way are polynomials in the spectral parameter and
show that they commute with transfer matrix. Finally, we prove that the
Q-operators satisfy Baxter's TQ-equation and derive the explicit form of their
eigenvalues in terms of the Bethe roots.

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The categories of this paper are: nucl-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga