Melo, C. A. M. de [UNESP]Medeiros, L. G.Pompeia, P. J.2015-10-212015-10-212015-02-28Modern Physics Letters A, v. 30, n. 6, 14 p., 2015.0217-7323http://hdl.handle.net/11449/128976We investigate the causal structure of general nonlinear electrodynamics and determine which Lagrangians generate an effective metric conformal to Minkowski. We also prove that there is only one analytic nonlinear electrodynamics not presenting birefringence.14engNonlinear electrodynamicsEffective metricsPhoton propagationArtigo10.1142/S021773231550025XWOS:000349849200003Acesso restrito