Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variational Approach to the Dynamics of Bose-Einstein Condensates.I
  --Variational Ansatz and Quantum Dynamics--   Variational method is applied to describe Bose-Einstein condensates (BEC)
interacting via a pseudo-potential, taking into account quantum fluctuations
around the mean field by the Gaussian approximation. Contributions from the
pair-wise scattering by the singular potential should be removed carefully to
avoid double countings in the perturbation series in terms of original bare
interaction. We show that this procedure removes all dangerous terms which
contain divergences.

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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas