相关论文: Insights from Melvin-Kerr-Newman spacetimes
After a brief summary of the basic properties of stationary spacetimes representing rotating, charged black holes in strong axisymmetric magnetic fields, we concentrate on extremal cases, for which the horizon surface gravity vanishes. We…
For extremal black holes, one can construct simpler, limiting spacetimes that describe the geometry near degenerate horizons. Since these spacetimes are known to have enhanced symmetry, the limiting objects coincide for different solutions.…
Magnetic fields surrounding spinning black holes can confine radiation and trigger superradiant instabilities. To investigate this effect, we perform the first fully-consistent linear analysis of the Ernst spacetime, an exact solution of…
The Kerr-Newman metric is the unique vacuum solution of the General Relativistic field equations, in which any singularities or spacetime pathologies are hidden behind horizons. They are believed to describe the spacetimes of massive…
We prove a perturbative result concerning the uniqueness of Kerr-Newman family of black holes: given an asymptotically flat space-time with bifurcate horizons, if it agrees with a non-extremal Kerr-Newman space-time asymptotically flat at…
We present a new exact solution of Einstein-Maxwell field equations which represents a rotating black hole with both electric and magnetic charges immersed in a universe which itself is also rotating and magnetized, i.e. the dyonic…
Analyzing exact solutions of the Einstein-Maxwell equations in the Kerr-Schild formalism we show that black hole horizon is instable with respect to electromagnetic excitations. Contrary to perturbative smooth harmonic solutions, the exact…
We determine all infinitesimal transverse deformations of extreme horizons in Einstein-Maxwell theory that preserve axisymmetry. In particular, we show that the general static transverse deformation of the AdS(2) X S(2) near-horizon…
A new proof of the uniqueness of the Kerr-Newman black hole solutions amongst asymptotically flat, stationary and axisymmetric electro-vacuum spacetimes surrounding a connected Killing horizon is given by means of an explicit construction…
The theory of $f(R)$ gravity with constant curvature (i.e. constant scalar curvature) admits rotating and charged black hole solutions obtained from the Kerr-Newman-(A)dS metrics of general relativity through appropriate rescalings of the…
We study the gravito-electromagnetic perturbations of the Kerr-Newman (KN) black hole metric and identify the two $-$ photon sphere and near-horizon $-$ families of quasinormal modes (QNMs) of the KN black hole, computing the frequency…
Associated to every stationary extremal black hole is a unique near-horizon geometry, itself a solution of the field equations. These latter spacetimes are more tractable to analyze and most importantly, retain properties of the original…
By considering charged black hole solutions of a one parameter family of two dimensional dilaton gravity theories, one finds the existence of quantum mechanically stable gravitational kinks with a simple mass to charge relation. Unlike…
Any spacetime containing a degenerate Killing horizon, such as an extremal black hole, possesses a well-defined notion of a near-horizon geometry. We review such near-horizon geometry solutions in a variety of dimensions and theories in a…
We study stationary black holes in the presence of an external strong magnetic field. In the case where the gravitational backreaction of the magnetic field is taken into account, such an scenario is well described by the Ernst-Wild…
In this paper, we construct scalarized rotating black holes within the framework of Einstein-Maxwell-scalar models. These models incorporate non-minimal couplings that can induce tachyonic instabilities, leading to the spontaneous…
Melvin-Kerr black hole represents a generalization of the Kerr black hole to the case of a non-vanishing external magnetic field via the Harrison transformation. Conformal mechanics related to the near horizon limit of such a black hole…
We exploit the near-horizon conformal symmetry of rapidly spinning black holes to determine universal properties of their magnetospheres. Analytic expressions are derived for the limiting form of the magnetosphere in the near-horizon…
In this thesis, we present new exact solutions of Einstein-Maxwell's field equations, with the most general case being the dyonic Kerr-Newman black hole in a Melvin-swirling universe, obtained analytically using the Ehlers-Harrison…
Thanks to the recent advent of the event horizon telescope (EHT), we now have the opportunity to test the physical ramifications of the strong-field near-horizon regime for astrophysical black holes. Herein, emphasizing the trade-off…