Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A synthetic electric force acting on neutral atoms   Electromagnetism is a simple example of a gauge theory where the underlying
potentials -- the vector and scalar potentials -- are defined only up to a
gauge choice. The vector potential generates magnetic fields through its
spatial variation and electric fields through its time-dependence. We
experimentally produce a synthetic gauge field that emerges only at low energy
in a rubidium Bose-Einstein condensate: the neutral atoms behave as charged
particles do in the presence of a homogeneous effective vector potential. We
have generated a synthetic electric field through the time dependence of an
effective vector potential, a physical consequence even though the vector
potential is spatially uniform.

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The categories of this paper are: gr-qc
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The categories of this paper are: q-bio
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The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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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: adap-org
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
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The categories of this paper are: math