Evolution of braneworld Kerr-Newman naked singularities

We study evolution of the braneworld Kerr-Newman (K-N) naked singularities, namely their mass M, spin a, and tidal charge b characterizing the role of the bulk space, due to matter in-falling from Keplerian accretion disk. We construct the evolution in two limiting cases applied to the tidal charge. In the first case we assume b = const during the evolution, in the second one we assume that the dimensionless tidal charge beta b/M-2 = const. For positive values of the tidal charge the evolution is equivalent to the case of the standard K-N naked singularity under accretion of electrically neutral matter. We demonstrate that counterrotating accretion always converts a K-N naked singularity into an extreme K-N black hole and that the corotating accretion leads to a variety of outcomes. The conversion to an extreme K-N black hole is possible for naked singularity with dimensionless tidal charge beta < 0.25, and beta is an element of (0.25, 1) with sufficiently low spin. In other cases the accretion ends in a transcendental state. For 0.25 < beta < 1 this is a mining unstable K-N naked singularity enabling formally unlimited energy extraction from the naked singularity. In the case of beta > 1, the corotating accretion creates unlimited torodial structure of mater orbiting the naked singularity. Both nonstandard outcomes of the corotating accretion imply a transcendence of such naked singularity due to nonlinear gravitational effects.

Automated summary

We study the evolution of the braneworld Kerr-Newman (K-N) naked singularities with a focus on the influence of tidal charge. We find that counterrotating accretion transforms a K-N naked singularity into an extreme black hole, while corotating accretion leads to various outcomes. Notably, a low-spin naked singularity with a dimensionless tidal charge less than 0.25 can be converted into an extreme black hole, whereas other cases result in transcendent states.