Probing nonlinear electromagnetic cosmological models with GRBs.

Nonlinear electrodynamics, as a source of Einstein’s equations, generates a cosmological model with a phase of cosmic acceleration and without an initial singularity, thus pointing to a way of solving two important problems in cosmology. We study the range of consistency of a model based in a Born-Infeld Lagrangian using Supernovae Ia (SNe Ia) and Gamma-Ray Bursts (GRBs). We use the sample of 59 high-redshift GRBs reported by Wei (2010), calibrated at low redshifts with the Union 2 sample of SNe Ia, thus avoiding the circularity problem.