L. Nobili

Photon trajectories in the Kerr-Newman metric

Gives a detailed description of the null trajectories in the Kerr-Newman metric. Interesting results which were not expected from what was known in the uncharged case are a considerable enhancement of the energy storage in a restricted region around the source in the naked singularity case and the singularity is completely disconnected from the asymptotic region in the sense that no photon can reach it even in the equatorial plane.

Charged singularities: repulsive effects

The repulsive phenomena which a particle experiences in the vicinity of a naked singularity are investigated in the Kerr-Newmann space-time. The aim is to extend the knowledge of this fact to charged solutions and to have a direct indication of how, in these situations, the gravitational and electrostatic interactions are competing.