Null singularity on nonsingular spacetime

Abstract

It is known that when coupled to nonlinear electrodynamics (NLED), Einstein’s equations can have nonsingular black hole (BH) solutions. For such BH the absence of horizon poses no violation of cosmic censorship theorem. In this work we show that the horizonless nonsingular BH charged with NLED, viewed from photon’s perspective, ironically is also responsible for the existence of singularity in its null geodesics. This is due to fact that the effective geometry gives additional conformal factor to the metric. For massive particles, on the other hand, the spacetime is still perfectly regular.