13 papers
Charged Kerr--Levi-Civita geometries in Einstein--Maxwell and low-energy heterotic string theory
Haryanto M. Siahaan
We construct and compare two charged rotating extensions of the Kerr--Levi-Civita geometry. In Einstein--Maxwell theory, a fixed magnetic Kerr--Newman Ernst representative is inver…
Kerr--NUT--Levi-Civita geometries from Ernst inversion: axis structure, curvature singularities, and the Manko--Ruiz parameter
Haryanto M. Siahaan
We construct and analyze stationary, axisymmetric vacuum metrics obtained by magnetic Ernst inversion of Kerr-NUT with Manko-Ruiz parameter and pre-inversion twist constant …
Zipoy--Voorhees spacetime with Maxwell and dilaton fields: exact solution and equatorial geodesics
Haryanto M. Siahaan
We derive a new exact solution of four-dimensional Kaluza-Klein theory by applying the uplift-boost-reduction procedure to the Zipoy-Voorhees vacuum seed. The resulting Zipoy-Voorh…
Leading weak-field magnetic corrections to charged scalar quasinormal modes of Kerr black holes in the Melvin--Kerr geometry
Haryanto M. Siahaan
We compute the leading magnetic corrections to the charged-scalar quasinormal-mode (QNM) spectrum of a Kerr black hole immersed in a weak external magnetic field, working in the Me…
Meissner Effect in Kerr--Bertotti--Robinson Spacetime
Haryanto M. Siahaan
We establish the black-hole Meissner effect for extremal Kerr--Bertotti--Robinson (Kerr--BR) black holes, which are exact solutions of the Einstein--Maxwell equations describing a…
Melvin-Zipoy-Voorhees Spacetime and Circular Orbits
Haryanto M. Siahaan
We construct an exact magnetized generalization of the Zipoy-Voorhees spacetime by applying the magnetic Harrison transformation to a static seed with quadrupolar deformation param…