Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The dynamics of condensate shells: collective modes and expansion   We explore the physics of three-dimensional shell-shaped condensates,
relevant to cold atoms in "bubble traps" and to Mott insulator-superfluid
systems in optical lattices. We study the ground state of the condensate
wavefunction, spherically-symmetric collective modes, and expansion properties
of such a shell using a combination of analytical and numerical techniques. We
find two breathing-type modes with frequencies that are distinct from that of
the filled spherical condensate. Upon trap release and subsequent expansion, we
find that the system displays self-interference fringes. We estimate
characteristic time scales, degree of mass accumulation, three-body loss, and
kinetic energy release during expansion for a typical system of Rb87.

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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
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: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con