Related papers: 1/r - Potential Without Charge
It is well known that an identical pair of extremal Reissner-Nordstrom black holes placed a large distance apart will exert no force on each other. In this paper, I establish that the same result holds in a very large class of…
In the present work, we seek for static spherically symmetric solutions representing wormhole configurations in generalized Rastall gravity (GRG). In this theory, a varying coupling parameter could act as dark energy (DE) and thus, it can…
As the electron in the hydrogen atom, a bosonic field can bind itself to a black hole occupying a discrete infinite set of states. When (i) the spacetime is prone to superradiance and (ii) a confinement mechanism is present, some of such…
We consider static, spherically symmetric, electrically or/and magnetically charged configurations of a minimally coupled scalar field with an arbitrary potential $V(\phi)$ in general relativity. Using the inverse problem method, we obtain…
We investigate the gravitational field of static perfect-fluid in the presence of electric field. We adopt the equation of state $p(r)=-\rho(r)/3$ for the fluid in order to consider the closed ($S_3$) or the open ($H_3$) background spatial…
In this paper we study some features of the Reissner-Nordstr\"om metric both from an analytic and a visual point of view. We perform an accurate ray tracing and study of null geodesics in various situations. Among the issues we focus on are…
I examine the pair creation of black holes in spacetimes with a cosmological constant of either sign. I consider cosmological C-metrics and show that the conical singularities in this metric vanish only for three distinct classes of black…
We extend Hintz's cosmological black hole gluing result to the Einstein-Maxwell system with positive cosmological constant by gluing multiple Reissner-Nordstr\"om or Kerr--Newman--de Sitter black holes into neighbourhoods of points in the…
With the means of Schrodinger equation a two electron problem is considered. It is shown that electrons in a periodic potential might experience effective attraction without any mediating agents; which means electrons in HTSC might have…
It has recently been demonstrated that static spatially regular scalar fields, which are non-minimally coupled to the electromagnetic field of a charged central black hole, can be supported in the exterior regions of the black-hole…
A particular type of coupling of the dilaton field to the metric is shown to admit a simple geometric interpretation in terms of a volume element density independent from the metric. For dimension n = 4 two families of either magnetically…
We demonstrate that the Schwarzschild black hole can be ``resolved'' into bound states of Reissner-Nordstr\"om black holes in four dimensions. These bound states closely resemble the Schwarzschild geometry from the asymptotic region up to…
We explicitly determine the expression of the electrostatic potential generated by a point charge at rest in the Schwarzschild black hole pierced by a cosmic string. We can then calculate the electrostatic self-energy. From this, we find…
We discuss the limit of vanishing $G$ (Newton's constant of universal gravitation) of the maximal analytically extended Kerr--Newman electrovacuum spacetimes {represented in Boyer--Lindquist coordinates}. We investigate the topologically…
The stress-energy tensor for the massless spin 1/2 field is numerically computed outside and on the event horizons of both charged and uncharged static non-rotating black holes, corresponding to the Schwarzschild, Reissner-Nordstrom and…
We study the formation and perturbation of black holes by null fluxes of neutral matter in a quadratic extension of General Relativity formulated a la Palatini. Working in a spherically symmetric space-time, we obtain an exact analytical…
We consider null geodesics in the exterior region of a subextremal Kerr spacetime. We show that most well-known fundamental properties of null geodesics can be represented on one plot. In particular, one can see immediately that the…
In this work, we explore the properties of timelike geodesic for particles with zero energy. We found some similarities between geodesic motion in Schwarzschild black hole and timelike geodesics for particles with zero energy. We show, that…
We present a traversable-wormhole solution of the gravitational field equation of General Relativity without need of exotic matter (exotic matter can, for example, have negative energy density and vanishing isotropic pressure). Instead of…
We consider the self-potential and the self-force for an electrically charged particle at rest in the massive wormhole space-time. We develop general approach for the renormalization of electromagnetic field of such particle in the static…