We present a large family of twisting and expanding solutions to the Einstein-Maxwell equations of algebraic type D, for which the two double principal null directions (PNDs) of the Weyl tensor are not aligned with the null eigendirections of the Faraday tensor. In addition to systematically deriving this new class, we present its various metric forms and convenient parameterizations. We show that in Boyer-Lindquist-type coordinates these solutions depend on 7 parameters, namely the Kerr and NUT (Newman-Unti-Tamburino) twist parameters a and l, mass parameter m, acceleration $\alpha$, strength of the Maxwell field |c|, and angular parameters $\beta$ $\gamma$ that represent two duality rotations of the Faraday tensor, which include the rotation between the electric and magnetic charges generating the aligned part of the Maxwell field. This coordinate parameterization, analogous to the Griffiths-Podolský form of the Plebański-Demiański solutions, allows us to perform various limits, explicitly identify the subcases, and determine the physical interpretation of the new class. Interestingly, by considering the limit with no acceleration ($\alpha\to 0$), one obtains either the famous Kerr-Newman-NUT black holes (if the parameter $|c|$ remains constant) or the novel Kerr-Bertotti-Robinson black holes, announced recently in our work [Phys. Rev. Lett. 135 (2025) 18, 181401] (if $\alpha\to 0$ while $\alpha |c|=const.$). We may thus conclude that this new class of spacetimes represents twisting charged accelerating black holes, immersed in an external magnetic (or electric) field. In the non-twisting subcase, we obtain the previously known solution of Van den Bergh-Carminati.
New class of rotating charged black holes in the external Bertotti-Robinson (electro)magnetic field
Next Seminar
Dynamics and perturbations of Geometric Inflation assisted by a scalar field in the early Universe
Next Journal Club
TBA
Black Hole Workshops
Next workshop:
XVIII Black Holes Workshop, Lisbon, 2025
18-19 December 2025
Previous workshops in the series:
I Black Holes Workshop, Porto, 2008
II Black Holes Workshop, Lisbon, 2009
III Black Holes Workshop, Minho, 2010
IV Black Holes Workshop, Aveiro, 2011
V Black Holes Workshop, Lisbon, 2012
VI Black Holes Workshop, Minho 2013
VII Black Holes Workshop, Aveiro 2014
VIII Black Holes Workshop, Lisbon 2015
IX Black Holes Workshop, Minho 2016
X Black Holes Workshop, Aveiro 2017
XI Black Holes Workshop, Lisbon, 2018
XII Black Holes Workshop, Minho, 2019
XIII Black Holes Workshop, Lisbon, 2020
XIV Black Holes Workshop, Aveiro, 2021
XV Black Holes Workshop, Lisbon, 2022
XVI Black Holes Workshop, Porto, 2023
XVII Black Holes Workshop, Aveiro, 2024
Numerical data
NewFunFICO network
Our group coordinates the Marie Sklodowska Curie Staff Exchange NewFunFiCO network (Jan 2023- Dec 2026)
More info here
FunFiCO Network
Our group coordinates the Marie Curie RISE FunFiCO network (Dec 2017- Dec 2023)
More info here
EuCAPT Consortium
GWVerse COST
StronGrHEP Network
Our group was part of the RISE StronGrHEP network (2016-2019)
Meetings:
Paris, 12-13 May 2016
Azores, 3-8 July 2017
Osaka, 4-8 September 2017
NRHEP Network Meetings
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
First Meeting:
9-13 July 2012, Aveiro, Portugal
Second Meeting:
11-14 March 2013, Lisbon, Portugal
Third Meeting:
6-10 January 2014, Mississippi, USA
Fourth Meeting:
7-10 July 2015, Rome, Italy
Fifth Meeting:
28 Sep-2 Oct 2015, Belém, Brazil
Ph.D. and Post-doctoral opportunities
Contact us If you are interested in pursuing graduate studies/research in our group.
Information for prospective Ph.D. students can be found here.
Past Ph.D. theses from our group can be found here.
Working as a researcher in Portugal - a quick guide.
Good Research Practices for New PhD students - a quick guide.