Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Deformation of a Trapped Fermi Gas with Unequal Spin Populations   The real-space densities of a polarized strongly-interacting two-component
Fermi gas of $^6$Li atoms reveal two low temperature regimes, both with a
fully-paired core. At the lowest temperatures, the unpolarized core deforms
with increasing polarization. Sharp boundaries between the core and the excess
unpaired atoms are consistent with a phase separation driven by a first-order
phase transition. In contrast, at higher temperatures the core does not deform
but remains unpolarized up to a critical polarization. The boundaries are not
sharp in this case, indicating a partially-polarized shell between the core and
the unpaired atoms. The temperature dependence is consistent with a tricritical
point in the phase diagram.

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The categories of this paper are: cs
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The categories of this paper are: physics
37
The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
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The categories of this paper are: nlin
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The categories of this paper are: stat
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The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ph