Kerr black hole in a uniform Bertotti-Robinson magnetic field: An exact solution

Abstract

A new class of exact spacetimes in Einstein's gravity, which are Kerr black holes immersed in an external magnetic (or electric) field that is asymptotically uniform and oriented along the rotational axis, is presented. These are axisymmetric stationary solutions to the Einstein-Maxwell equations such that (unlike in the Plebanski-Demianski spacetime) the null directions of the Faraday tensor are not aligned with neither of the two principal null directions of the Weyl tensor of algebraic type D (unlike the Kerr-Melvin spacetime). Three physical parameters are the black hole mass $m$, its rotation $a$, and the external field value $B$. For vanishing $B$ the metric directly reduces to standard Boyer-Lindquist form of the Kerr black hole, while for zero $m$ we recover conformally flat Bertotti-Robinson universe with a uniform Maxwell field. For zero $a$ the spacetime is contained in the Van den Bergh-Carminati solutions which can be understood as the Schwarzschild black hole in a magnetic field. Our family of black holes with non-aligned Maxwell hair - that can be called the Kerr-Bertotti-Robinson (Kerr-BR) black holes - may find application in various studies ranging from mathematical relativity to relativistic astrophysics.

8 pages, 2 figures; final (slightly extended) form of the paper published in Phys. Rev. Lett. 135 (2025) 181401

References in corpus (8)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• Accelerating Kerr-Newman black holes in (anti-)de Sitter space-time
• New form of all black holes of type D with a cosmological constant
• New class of rotating charged black holes with nonaligned electromagnetic field
• Revisiting black holes of algebraic type D with a cosmological constant
• Kerr-Newman black hole in a Melvin-swirling universe
• Black holes of type D revisited: relating their various metric forms
• Most general Type-D Black Hole and the Accelerating Reissner-Nordstrom-NUT-(A)dS solution

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• Static hairy black hole in 4D General Relativity
• Anisotropic matter and nonlinear electromagnetics black holes
• Various metric forms of all type D black holes and their application
• Black holes in $f(R,T)$ gravity coupled with Euler-Heisenberg electrodynamics