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arXiv · 1607.08879

Electromagnetic duality anomaly in curved spacetimes

I. Agullo·A. del Rio·J. Navarro-Salas
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Abstract

The source-free Maxwell action is invariant under electric-magnetic duality rotations in arbitrary spacetimes. This leads to a conserved classical Noether charge. We show that this conservation law is broken at the quantum level in presence of a background classical gravitational field with a non-trivial Chern-Pontryagin invariant, in a parallel way to the chiral anomaly for massless Dirac fermions. Among the physical consequences, the net polarization of the quantum electromagnetic field is not conserved.

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I. Agullo, A. del Rio, J. Navarro-Salas. 2017-03-15. Electromagnetic duality anomaly in curved spacetimes. https://doi.org/10.1103/physrevlett.118.111301

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