Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Investigation of the momentum distribution of an excited BEC by free
  expansion: coupling with collective modes   We investigate the evolution of the momentum distribution of a Bose-Einstein
condensate subjected to an external small oscillatory perturbation as a
function of the in-trap evolution of the condensate after the external
perturbation is switched-off. Besides changing its momentum distribution, we
observe that the cloud distributes the input energy among its normal collective
modes, displaying center-of-mass dipolar mode and quadrupolar mode. While the
dipolar mode can be easily disregarded, we show that the momentum distribution
is closely tied to the quadrupolar oscillation mode. This convolution hinders
the actual momentum distribution.

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The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph