Modelos relativistas de discos de polvo magnetizados en un espaciotiempo conformestático axialmente simétrico

Abstract

An infinite family of new solutions of the Einstein-Maxwell equations for axially symmetric conformastatic spacetimes is presented. This family of solutions describe thin dust disks made of material sources with a surface conduction current. The solutions are obtained by expressing the metric function and the magnetic potential in terms of an auxiliary function which satisfies the Laplace equation, a characteristic property of the conformastatic spacetimes. By introducing then a finite discontinuity on the first derivatives of the metric tensor, solutions with a delta function type singularity with support on the hypersurface z = 0 are obtained, describing so infinitesimally thin disks of infinite extension. Then, the surface energy-momentum and the surface current density of the disk are obtained by using the formalism of tensorial distributions and their physical content is analyzed. It was found that the energy density behaves well everywhere, that the energy-momentum tensor satisfies all the energy conditions and that, although the discs are of infinite extension, their total mass is finite. Furthermore, it is found that the curvature quadratic scalars and the electromagnetic invariants are regular everywhere, so that the spacetime is free of singularities. Finally, in order to illustrate the behavior of the family of thin disks, we consider the model for the first family member and graphically analyzes the behavior of the surface energy density and the surface current density. © 2014. Acad. Colomb. Cienc. Ex. Fis. Nat. All rights reserved.