Binary black hole system at equilibrium

TL;DR

This paper presents an exact analytical solution in General Relativity for two static black holes in equilibrium, maintained by an external gravitational field without additional matter or singular structures.

Contribution

It provides a novel explicit solution describing two black holes at equilibrium with a regular metric outside horizons, expanding understanding of black hole configurations.

Findings

Solution is completely regular outside horizons.

Balance achieved without extra matter or strings.

Discusses thermodynamic laws for the system.

Abstract

An exact and analytical solution of four dimensional vacuum General Relativity representing a system of two static black holes at equilibrium is presented. The metric is completely regular outside the event horizons, both from curvature and conical singularities. The balance between the two Schwarzschild sources is granted by an external gravitational field, without the need of extra matter fields besides gravity, nor strings or struts. The geometry of the solution is analysed. The Smarr law, the first and the second law of black hole thermodynamics are discussed.