The fields of a naked singularity and a black hole in mutual equilibrium

Recently Alekseev and Belinski have presented a new exact solution of the Einstein‐Maxwell equation which describes two Reissner‐Nordstrom (RN) sources in reciprocal equilibrium (no struts nor strings); one source is a naked singularity, the other is a black hole.

In this paper we use the Alekseev‐Belinki solution in the special case in which the charge of the black hole is zero—therefore we have a naked singularity near a neutral black hole. We give the plots of the electric force lines in both the cases in which the naked singularity has a mass comparable with the black hole and in which it is much smaller. The analysis of this latter case confirm the goodness of the Hanni‐Ruffini approximation.