2016/04/09 by Gerold O. Schellstede, Volker Perlick, Claus Lämmerzahl · 31 citations
Engineering · Physics and Astronomy · #Causality (physics) #Class (philosophy) #Electromagnetic field #Field (mathematics) #Geodesic #Geophysics and Sensor Technology #Nonlinear system #Quantum Electrodynamics and Casimir Effect #Quantum and Classical Electrodynamics #Tensor (intrinsic definition) #gr-qc
paper · pdf · doi:10.1002/andp.201600124
published in Annalen der Physik 528(9-10), 738-749 (Wiley) · 21 pages
arxiv created 2016/04/09 · openalex created_date 2016/06/24 · openalex publication_date 2016/07/14 · arxiv updated 2016/11/03 · openalex updated_date 2026/08/05
We investigate the Plebański class of electrodynamical theories, i.e., theories of nonlinear vacuum electrodynamics that derive from a Lorentz‐invariant Lagrangian (or Hamiltonian). In any such theory the light rays are the lightlike geodesics of two optical metrics that depend on the electromagnetic background field. A set of necessary and sufficient conditions is found whose fulfillment secures that the optical metrics are causal in the sense that the light rays are lightlike or timelike with respect to the underlying space‐time metric. Thereupon we derive conditions on the Lagrangian, or the Hamiltonian, of the theory such that the causality conditions are satisfied for all allowed background fields. (The allowed values of the field strength tensor are those for which the excitation tensor is finite and real.) The general results are illustrated with several examples. image