Electromagnetic duality anomaly in curved spacetimes
General Relativity and Quantum Cosmology
2017-03-22 v2 High Energy Physics - Theory
Mathematical Physics
math.MP
Quantum Physics
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.
Cite
@article{arxiv.1607.08879,
title = {Electromagnetic duality anomaly in curved spacetimes},
author = {I. Agullo and A. del Rio and J. Navarro-Salas},
journal= {arXiv preprint arXiv:1607.08879},
year = {2017}
}
Comments
5 pages. Typos corrected. Some points clarified. To appear in Phys. Rev. Lett