Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective excitations of degenerate Fermi gases in anisotropic
  parabolic traps   The hydrodynamic low-frequency oscillations of highly degenerate Fermi gases
trapped in anisotropic harmonic potentials are investigated. Despite the lack
of an obvious spatial symmetry the wave-equation turns out to be separable in
elliptical coordinates, similar to a corresponding result established earlier
for Bose-condensates. This result is used to give the analytical solution of
the anisotropic wave equation for the hydrodynamic modes.

5
The categories of this paper are: gr-qc
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The categories of this paper are: econ
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th