Singularity-free Bianchi spaces with nonlinear electrodynamics

Abstract

In this paper we present an analysis to determine the existence of singularities in spatially homogeneous anisotropic universes filled with nonlinear electromagnetic radiation. These spaces are conformal to Bianchi spaces admitting a three parameter group of motions G${}_3$. For these models we study geodesic completeness. It is shown that with nonlinear electromagnetic field some of the Bianchi spaces are geodesically complete, like G${}_3$IX and G${}_3$VIII; however, completeness depends on the curvature of the space. When certain topology is assumed, Bianchi G${}_3$IX presents geodesics that are imprisoned. It is surprising that in the linear limit (Maxwell field) the spacetimes are singularity-free even if the curvature parameter is zero.

10 pages, 3 figures