Regular black holes with flux tube core

TL;DR

This paper introduces a class of regular black hole solutions with flux tube cores, achieved by gluing a tubelike metric to a black hole region, resulting in globally regular spacetimes without singularities or apparent horizons.

Contribution

It presents a novel method to construct regular black holes by combining tubelike geometries with black hole regions, removing singularities and horizons through smooth gluing.

Findings

Constructed globally regular black hole solutions without singularities.

Demonstrated the method with matter models including vacuum fluid, matter with linear equation of state, and scalar phantom fields.

Extended the approach to non-spherical, distorted metrics.

Abstract

We consider a class of black holes for which the area of the two-dimensional spatial cross-section has a minimum on the horizon with respect to a quasiglobal (Krusckal-like) coordinate. If the horizon is regular, one can generate a tubelike counterpart of such a metric and smoothly glue it to a black hole region. The resulting composite space-time is globally regular, so all potential singuilarities under the horizon of the original metrics are removed. Such a space-time represents a black hole without an apparent horizon. It is essential that the matter should be non-vacuum in the outer region but vacuumlike in the inner one. As an example we consider the noninteracting mixture of vacuum fluid and matter with a linear equation of state and scalar phantom fields. This approach is extended to distorted metrics, with the requirement of spherical symmetry relaxed.