Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exact solution of the infinite-U Hubbard problem and other models in one
  dimension   An interacting spin-fermion model is exactly solved on an open chain. In a
certain representation, it is the nearest-neighbor Hubbard model in the limit
of infinite $U$ (local interaction). Exact solution of its complete energy
eigen-spectrum is accomplished by introducing a unitary transformation which
maps the original problem to a tight-binding model of the fermions only.
Physically, the exact solution implies the absence of Nagaoka ferromagnetism in
the ground state for arbitrary electron densities. The present method solves a
class of very general models exactly. Few more problems are discussed as an
application of this unitary transform method.

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The categories of this paper are: hep-th
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The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: eess