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arXiv · 1807.10168

Projective symmetries and induced electromagnetism in metric-affine gravity

Bert Janssen·Alejandro Jimenez-Cano
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Abstract

We present a framework in which the projective symmetry of the Einstein-Hilbert action in metric-affine gravity is used to induce an effective coupling between the Dirac lagrangian and the Maxwell field. The effective $U(1)$ gauge potential arises as the trace of the non-metricity tensor $Q_{μa}{}^a$ and couples in the appropriate way to the Dirac fields to in order to allow for local phase shifts. On shell, the obtained theory is equivalent to Einstein-Cartan-Maxwell theory in presence of Dirac spinors.

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Bert Janssen, Alejandro Jimenez-Cano. 2018-10-17. Projective symmetries and induced electromagnetism in metric-affine gravity. https://doi.org/10.1016/j.physletb.2018.10.032

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