Extreme black points in Born–Infeld electrodynamics

This article considers the spacetime structure of a charged black hole in the nonlinear Born–Infeld electrodynamics. We discuss a special state of such a black hole in the form of a “black point” with a doubly degenerate horizon, for which the pseudo-Riemannian spacetime has a timelike singularity, and the effective spacetime for photons turns out to be everywhere regular. This property makes extreme black points an intermediate state between traditional and absolutely regular black holes.