Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum effects in $QED_{3+1}$ with an extra compactified dimension   We evaluate one-loop effects for $QED_{3+1}$ in the presence of an extra
compactified dimension, in a non-trivial vacuum for the gauge field, such that
a non-vanishing magnetic flux is encircled along the extra dimension. We obtain
the vacuum polarization tensor and evaluate the exact parity breaking term.

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The categories of this paper are: atom-ph
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The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
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The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex