2026-04-13T03:00:30Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/2206482025-12-05T16:14:32Zcom_2072_1057col_2072_478823col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Mezincescu, Luca author Russo, J. G. (Jorge Guillermo) author Townsend, Paul K. author 2025-04-25T16:17:56Z 2025-04-25T16:17:56Z 2024 2025-04-25T16:17:56Z Abstract: Using Hamiltonian methods, we fnd six relativistic theories of nonlinear electrodynamics for which plane wave perturbations about a constant uniform background are not birefringent. All have the same conformal strong-feld limit to Bialynicki-Birula (BB) electrodynamics, but only four avoid superluminal propagation: Born-Infeld (BI), its non-conformal “extreme” limits (electric and magnetic) and the conformal BB limit. The quadratic dispersion relation of BI is shown to degenerate in the extreme limits to a pair of linear relations, which become identical in the BB limit. Sistemes hamiltonians Teoria de camps (Física) Electrodinàmica Hamiltonian systems Field theory (Physics) Electrodynamics Hamiltonian birefringence and Born-Infeld limits