Related papers: Black holes with current loops revisited
This note surveys how energy generation and strengthening has been used to prove Morawetz estimates for various field equations in Minkowski space, the exterior of the Schwarzschild spacetime, and the exterior of the Kerr spacetime. It…
We derive alternate and new closed-form analytic solutions for the non-equatorial eccentric bound trajectories, $\{ \phi \left( r, \theta \right)$, $\ t \left( r, \theta \right),\ r \left( \theta \right) \}$, around a Kerr black hole by…
We identify a set of higher-derivative extensions of Einstein-Maxwell theory that allow for spherically symmetric charged solutions characterized by a single metric function $f(r)=-g_{tt}=1/g_{rr}$. These theories are a non-minimally…
It was recently shown that (near-)extremal Kerr black holes are sensitive probes of small higher-derivative corrections to general relativity. In particular, these corrections produce diverging tidal forces on the horizon in the extremal…
For an uncharged test particle in the Kerr-Bertotti-Robinson spacetime, solutions of two major types of orbits are presented, both in exact forms. First, for both prograde and retrograde motions, the radii of innermost stable circular…
The electric charge on rotating black holes is calculated to be ~ BJ in the force-free configuration of Ghosh (2000), with a horizon flux of ~ BM^2. This charge is gravitationally weak for B ~ 10^{15} G, so that the Kerr metric applies.…
We present analytical solutions describing a family of both inwardly and outwardly spiralling orbits in the Kerr spacetime. The solutions are exact, and remarkable for their simplicity. These orbits all have the angular momentum and energy…
The problem of the existence of particles with negative energies inside and outside of Schwarzschild, charged and rotating black holes is investigated. Different definitions of the energy of the particle inside the Schwarzschild black hole…
In mimetic gravity, we derive $D$-dimension charged black hole solutions having flat or cylindrical horizons with zero curvature boundary. The asymptotic behaviours of these black holes behave as (A)dS. We study both linear and nonlinear…
We provide an explicit, closed and compact expression for the Debye superpotential of a circular source. This superpotential is obtained by integrating the Green function of Teukolsky Master Equation (TME). The Debye potential itself is…
We study the evolution of strings in the equatorial plane of a Kerr-Newmann black hole. Writting the equations of motion and the constraints resulting from Hamilton's principle, three classes of exact solutions are presented, for a closed…
With the Komar mass formula we calculate the electromagnetic energy for a charged Kerr black hole in a uniform magnetic field. We find that the total electromagnetic energy takes the minimum when the Kerr black hole possesses a non-zero net…
We consider a stationary metric immersed in a uniform magnetic field and determine general expressions for the epicyclic frequencies of charged particles. Applications to the Kerr--Newman black hole is reach of physical consequences and…
Based on the $\phi$-mapping topological current theory, we show that the presence of the black hole leaves fractional baryon charge outside the horizon in the Einstein-Skyrme theory. A topological current is derived from the Einstein-Skyrme…
Since the Weak Cosmic Censorship Conjecture was proposed, research on this conjecture has been ongoing. This paper explores the conjecture in black holes that are closer to those existing in the real universe (i.e., rotating black holes…
Recently, it was shown that the extreme Kerr black hole is the only candidate for a (Kerr) black hole limit of stationary and axisymmetric, uniformly rotating perfect fluid bodies with a zero temperature equation of state. In this paper,…
In this work, a new class of slowly rotating black hole solutions in dilaton gravity has been obtained where dilaton field is coupled with nonlinear Maxwell invariant. The background space-time is a stationary axisymmetric geometry. Here,…
Generalizing previous work we propose how to superpose spinning black holes in a Kerr-Schild initial slice. This superposition satisfies several physically meaningful limits, including the close and the far ones. Further we consider the…
The rotational energy of a Kerr black hole is often invoked as the free energy source that powers compact astrophysical systems An important question concerning the energy extraction mechanism is whether a Kerr black hole can communicate…
We investigate possible end-points of the superradiant instability for a charged black hole with a reflecting mirror. By considering a fully coupled system of gravity and a charged scalar field, hairy black hole solutions are obtained. The…