Magnetized dynamical black holes
arXiv:2601.08628 · doi:10.1088/1475-7516/2026/05/005
Abstract
We construct a novel exact solution of the Einstein-scalar-Maxwell equations describing a dynamical black hole immersed in an external, time-dependent electromagnetic field. Motivated by the need for more realistic analytical black hole models, our construction incorporates two key ingredients often neglected in exact solutions: a fully dynamical cosmological background and the non-perturbative backreaction of external electromagnetic fields. The compact object is obtained by dressing a Schwarzschild black hole with a radially and temporally dependent scalar field, yielding a time-dependent generalization of the Fisher-Janis-Newman-Winicour solution within the Fonarev framework. The external electromagnetic field is generated via a Lie point symmetry of the Einstein-scalar-Maxwell system, which exports the effect of a Harrison transformation to dynamical settings provided a spacelike Killing vector is present. The resulting spacetime combines a spherically symmetric dynamical horizon with an axisymmetric electromagnetic field and exhibits a rich asymptotic structure mixing Friedmann-Lemaître-Robertson-Walker and Levi-Civita geometries. We show that the time dependence of the configuration plays a crucial role in potentially cloaking curvature singularities, which would otherwise be generically naked in the stationary limit. We analyze the geometric and physical properties of the solution, including its asymptotic behavior, algebraic classification, and the structure of trapped surfaces defining the dynamical horizon. Possible implications for primordial black holes and some astrophysical applications, as well as extensions to higher dimensions, are also discussed.
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References in corpus (30)
- Isolated and dynamical horizons and their applications
- McVittie's Legacy: Black Holes in an Expanding Universe
- Kerr-de Sitter Universe
- Non-symmetric trapped surfaces in the Schwarzschild and Vaidya spacetimes
- Foliation dependence of black hole apparent horizons in spherical symmetry
- Generating dynamical black hole solutions
- Black Holes in an Expanding Universe
- Higher dimensional black holes in external magnetic fields
- Primordial black holes in nonminimal derivative coupling inflation with quartic potential and reheating consideration
- Dynamical Black Holes: Approach to the Final State
- Evolving black holes from conformal transformations of static solutions
- Mixing "Magnetic'' and "Electric'' Ehlers--Harrison transformations: The Electromagnetic Swirling Spacetime and Novel Type I Backgrounds
- Revisiting Buchdahl transformations: New static and rotating black holes in vacuum, double copy, and hairy extensions
- Quasi-Local Black Hole Horizons: Recent Advances
- Kerr-Newman black hole in a Melvin-swirling universe
- Particle production from marginally trapped surfaces of general spacetimes
- Melvin Magnetic Fluxtube/Cosmology Correspondence
- Conformally Schwarzschild cosmological black holes
- Thakurta metric does not describe a cosmological black hole
- Black Hole in a Radiation-Dominated Universe
- Generating Solutions to the Einstein Field Equations
- Magnetic Fields in an Expanding Universe
- Building Cosmological Frozen Stars
- Geometrical origin of the Kodama vector
- Mean curvature flow and quasilocal mass for two-surfaces in Hamiltonian General Relativity
- Apparent horizons of the Thakurta spacetime and the description of cosmological black holes
- An exact model for evaporating primordial black holes in cosmological space-time
- Black hole regions containing no trapped surfaces
- Matching McVittie spacetimes
- Dynamics of localized Kaluza-Klein black holes in a collapsing universe