Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exact solution of the one-dimensional Hubbard model with arbitrary
  boundary magnetic fields   The one-dimensional Hubbard model with arbitrary boundary magnetic fields is
solved exactly via the Bethe ansatz methods. With the coordinate Bethe ansatz
in the charge sector, the second eigenvalue problem associated with the spin
sector is constructed. It is shown that the second eigenvalue problem can be
transformed into that of the inhomogeneous XXX spin chain with arbitrary
boundary fields which can be solved via the off-diagonal Bethe ansatz method.

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The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio