A tale of two dyons

Gérard Clément,Dmitri Gal'Tsov

doi:10.1016/j.physletb.2017.05.096

Abstract

We present a one-parameter family of stationary, asymptotically flat solutions of the Einstein–Maxwell equations with only a mild singularity, which are endowed with mass, angular momentum, a dipole magnetic moment and a quadrupole electric moment. We briefly analyze the structure of this solution, which we interpret as a system of two extreme co-rotating black holes with equal masses and electric charges, and opposite magnetic and gravimagnetic charges, held apart by an electrically charged, magnetized string which also acts as a Dirac–Misner string.

Highlights

Stationary asymptotically flat black holes with regular connected event horizons are known to be strongly limited by uniqueness theorems and given in the vacuum case by the Kerr metric, and in the electrovacuum case by the Kerr-Newman solution
It is a system of two extreme co-rotating black holes endowed with masses, NUT charges, electric and magnetic charges held apart by a magnetized, electrically charged string of negative tension, which is a Dirac and Misner string
As the Misner string does not extend to infinity, the solution is asymptotically flat

Summary

Introduction

Stationary asymptotically flat black holes with regular connected event horizons are known to be strongly limited by uniqueness theorems and given in the vacuum case by the Kerr metric, and in the electrovacuum case by the Kerr-Newman solution. It is worth noting that the possibility of violation of cosmic censorship in gravitational collapse has received more attention recently [8] In this short note (a more detailed version will be published elsewhere) we wish to draw attention to a new electrovacuum solution obtained some time ago by one of us [9] via an original generating technique which produces a one-parameter family of rotating electrovacuum solutions from a given static vacuum one. Application of this procedure to the static ZV metric generates a rotating solution with a magnetic dipole moment, which is the unique so far known rotating generalization of the ZV metric with non-integer γ, and has the advantage to be free from a naked ring singularity.

The solution

The horizons

The string

Summary and outlook