Hybrid black holes

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 thin null shells. The corresponding solution is called a “hybrid” black hole. The 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 nonrotating Weyl-distorted black hole. Properties of the hybrid black holes are briefly discussed.