https://doi.org/10.1140/epjp/s13360-024-05114-1
Regular Article
How the twofold light cone arises from nonlinear electrodynamics
Physics Department, Cinvestav, Av. Instituto Politecnico Nacional 2508, 07360, Mexico City, Mexico
a
nora.breton@cinvestav.mx
b
alfonso.acevedo@cinvestav.mx
Received:
19
February
2024
Accepted:
20
March
2024
Published online:
3
June
2024
We analyze the propagation of light signals in the context of nonlinear electrodynamics. As a general feature of the nonlinear theories, the superposition principle is no longer satisfied. In the electromagnetic theory, this is due to the self-interactions of the field and light propagation is governed by an effective or optical metric. We present a simple derivation of the two light cones that arise if the Lagrangian depends on the electromagnetic invariants in a nonlinear way. Using the algebraic properties of the electromagnetic tensor 
, we determine the dispersion relations from the eigenvalues of a Sturm–Liouville equation. It turns out that in the presence of a background field, light propagation can be slower or faster than the one in vacuum. We also derive the corresponding transport vector fields.
© The Author(s) 2024
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