Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: QED Coupling from a 5-D Kaluza-Klein Theory   We discuss the possibility to obtain, from a five-dimensional free spinor
Lagrangian, the Quantum Electro-Dynamics (QED) coupling via a Kaluza-Klein
reduction of the theory. This result is achieved taking a phase dependence of
the spinor field on the extra-coordinate and modifying the corresponding
connection. The five-dimensional spinor theory is covariant under the
admissible coordinates transformations and its four-dimensional reduction
provides the QED coupling term.

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The categories of this paper are: math-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph