Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Upper bound of one-magnon excitation and lower bound of effective mass
  for ferromagnetic spinor Bose and Fermi gases   Using a variational method, we derive an exact upper bound for one-magnon
excitation energy in ferromagnetic spinor gases, which limits the quantum
corrections to the effective mass of a magnon to be positive. We also derive an
upper bound for one-magnon excitation energy in lattice systems. The results
hold for both Bose and Fermi systems in $d$ dimensions as long as the
interaction is local and invariant under spin rotation.

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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: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex
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The categories of this paper are: cmp-lg