"Hybrid" Black Holes

TL;DR

This paper introduces a new class of black hole solutions called 'hybrid' black holes, formed by gluing Kerr and Weyl metrics at horizons using null shells, revealing combined features of rotation and distortion.

Contribution

It presents a novel method of constructing hybrid black holes by gluing Kerr and Weyl metrics with null shells, combining rotation and distortion effects.

Findings

The inner geometry matches non-rotating Weyl-distorted black holes.

The outer geometry is described by the Kerr metric with rotation.

The null shell's angular momentum induces the external black hole's rotation.

Abstract

We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.