scholarly journals Areas of the event horizon and stationary limit surface for a Kerr black hole

2000 ◽  
Vol 68 (8) ◽  
pp. 746-748 ◽  
Author(s):  
C. A. Pickett ◽  
J. D. Zund
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Kerr Black Hole ◽  
Limit Surface

scholarly journals Computing the temporal intervals by making a Throne-Morris wormhole from a Kerr black hole in the context of f(R,T) gravity

2021 ◽  
Vol 9 (07) ◽  
pp. 72-92
Author(s):  
Aruna Harikant ◽  
Sanjeevan Singha Roy ◽  
Deep Bhattacharjee
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Mouth Opening ◽  
Kerr Black Hole ◽  
Time Travel ◽  
Exotic Matter ◽  
Cauchy Horizon ◽  
Type Singularity ◽  
Temporal Intervals ◽  
Temporal Dimensions

In the paper we will proceed towards taking the larger root of  and make it equal to zero to remove the event horizon of a Kerr black hole (BH) in Boyer-Lindquist coordinates with a prevalent ring type singularity that can be smoothen by a tunneling approach of a spherinder thereby proceeding safely towards the Cauchy horizon with the deduced intervals computed in detail for the time travel in the Throne-Morris wormhole (WH) approach under  gravity without the presence of any exotic matter at the WH mouth thereby preserving the asymptotically solutions of flaring out conditions and mouth opening during the course of the journey through the Einstein-Rosen bridge. An approach has been organized in the paper in which not only time travel is possible without exotic matter but also time travel is flexible to past and future in the Einstein’s universe by eliminating all sorts of paradoxes by spatial sheath through 2D approach of temporal dimensions.

Extremal Kerr Black Holes, Naked Singularity & Wormholes

2020 ◽  
Author(s):  
Deep Bhattacharjee
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Angular Momentum ◽  
Event Horizon ◽  
Kerr Black Hole ◽  
Naked Singularity ◽  
Kerr Metric ◽  
Spin Angular Momentum ◽  
The Way

This paper is totally based on the mathematical physics of the Black holes. In Einstein’s theory of “General Relativity”, Schwarzschild solution is the vacuum solutions of the Einstein Field Equations that describes the gravity potential from outside the body of a spherically symmetric object having zero charge, zero mass and zero cosmological constant[1]. It was discovered by Karl Schwarzschild in 1916, a little more than a month after the publication of the famous GR and the singularity is a point singularity which can be best described as a coordinate singularity rather than a real singularity, however, the drawback of this theory is that it fails to take into account the real life scenario of black holes with charge and spin angular momentum. The black hole is based on event horizon and Schwarzschild radius. However, Physicists were trying to develop a metric for the real life scenario of a black hole with a spin angular momen-tum and ultimately the exact solution of a charged rotating black hole had been discovered by Roy Kerr in 1965 as the Kerr-Newman metric[2][3]. The Kerr metric is one of the toughest metric in physics and is the extensional generalization to a rotating body of the Schwarzschild metric. The metric describes the vacuum geometry of space-time around a rotating axially-symmetric black hole with a quasipotential event horizon. In Kerr metric there are two event hori-zons (inner and outer), two ergospheres and an ergosurface. The most important effect of the Kerr metric is the frame dragging (also known as Lense-Thirring Precession) is a distinctive prediction of General relativity. The first direct observation of the collision of two Kerr Black Holes has been discovered by LIGO in 2016 hence setting up a milestone of General Relativity in the history of Physics. Here, the Kerr metric has been introduced in the Boyer-Lindquist forms and it is derived from the Schwarzschild metric using the Spin-Coefficient formalism. According to the “Cosmic Censorship Hypothesis”, a naked singularity cannot exist in nature as nature always hides the singularity via an event horizon. However, in this paper I will prove the existence of the “Naked Singularity" taking the advantage of the Ring Singularity of the Kerr Black Hole and thereby making the way to manipulate the mathematics by taking the larger root of Δ as zero and thereby vanishing the ergosphere and event horizon making the way for the naked ring singularity which can be easily connected via a cylindrical wormhole and as ‘a wormhole is a black hole without an event horizon’ therefore, this cylindrical connection paved the way for the Einstein-Rosen Bridge allowing particles or null rays to travel from one universe to another ending up in a future directed Cauchy horizon while changing constantly from spatial to temporal and again spatial paving the entrance to another Kerr Black hole (which would act as a white hole) in the other universes. I will not go in detail about the contradiction of ‘Chronology Protection Conjecture” [4]whether the Stress-Energy-Momentum Tensor can violate the ANEC (Average Null Energy Conditions) or not with the values of less than zero or greater than, equal to zero, instead I will focus definitely on the creation of the mathematical formulation of a wormhole from a Naked Ring Kerr Singularity of a Kerr Black Hole without any event horizon or ergosphere. Another important thing to mention in this paper is that I have taken the time to be imaginary[5] as because, a singularity being an eternal point of time can only be smoothen out if the time is imaginary rather than real which will allow the particle or null rays inside a wormhole to cross the singularity and making entrance to the other universe. The final conclusion would be to determine the mass-energy equivalence principle as spin angular momentum increases with a decrease in BH mass due to the vanishing event horizon and ergosphere thereby maintaining the equivalence via apparent and absolute masses in relation to spin J along the orthogonal Z axis. A ‘NAKED SINGULARITY’ alters every parameters of a BH and to include this parameters along with affine spin coefficient, it has been proved that without any spin angular momentum the generation of wormhole and vanishing of event horizon and singularity is not possible.

scholarly journals Global embedding of the Kerr black hole event horizon into hyperbolic 3-space

2009 ◽  
Vol 80 (4) ◽  
Author(s):  
G. W. Gibbons ◽  
C. A. R. Herdeiro ◽  
C. Rebelo
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Kerr Black Hole

A charged black hole in a uniform magnetic field

1983 ◽  
Vol 61 (8) ◽  
pp. 1192-1197 ◽  
Author(s):  
K. D. Krori ◽  
Sumita Chaudhury ◽  
S. Dowerah
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Event Horizon ◽  
Gaussian Curvature ◽  
Uniform Magnetic Field ◽  
Kerr Black Hole ◽  
Charged Black Hole ◽  
Bonnet Theorem

We present here an investigation of the event horizon of a charged black hole embedded in a uniform magnetic field by studying the Gaussian curvature. It is shown that the Gauss–Bonnet theorem holds for this magnetized black hole and also for a magnetized Kerr black hole.

Research on the semiclassical theory and Hawking tunneling radiation of nonstationary Kerr black hole

2020 ◽  
Vol 35 (30) ◽  
pp. 2050193
Author(s):  
Tao Wang ◽  
Xinxing Wu ◽  
Qun-Chao Ding ◽  
Shu-Zheng Yang
Keyword(s):  
Black Hole ◽  
Dirac Equation ◽  
Thermodynamic Properties ◽  
Event Horizon ◽  
Kerr Black Hole ◽  
Semiclassical Theory ◽  
Tunneling Radiation ◽  
Jacobi Equations ◽  
Tunneling Behavior

In this paper, the tunneling radiations of spin 1/2 and spin 3/2 fermions from the nonstationary Kerr black hole are investigated. First, according to the Dirac equation and the Rarita–Schwinger equation, the Hamilton–Jacobi equations for spin 1/2 and 3/2 fermions are derived. Then, the tunneling behavior of fermions on the event horizon of the black hole is investigated. Finally, the thermodynamic properties of the nonstationary Kerr black hole are obtained.

scholarly journals TESTING THE KERR BLACK HOLE HYPOTHESIS

2011 ◽  
Vol 26 (33) ◽  
pp. 2453-2468 ◽  
Author(s):  
COSIMO BAMBI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Gravitational Collapse ◽  
State Of The Art ◽  
Kerr Black Hole ◽  
The State ◽  
Kerr Geometry

It is thought that the final product of the gravitational collapse is a Kerr black hole and astronomers have discovered several good astrophysical candidates. While there are some indirect evidences suggesting that the latter have an event horizon, and therefore that they are black holes, a proof that the spacetime around these objects is described by the Kerr geometry is still lacking. Recently, there has been an increasing interest in the possibility of testing the Kerr black hole hypothesis with present and future experiments. In this paper, I briefly review the state-of-the-art of the field, focusing on some recent results and works in progress.

scholarly journals Solutions of Kerr Black Holes subject to Naked Singularity and Wormholes

2020 ◽  
Author(s):  
Deep Bhattacharjee
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Kerr Black Hole ◽  
Naked Singularity ◽  
The Other ◽  
Cauchy Horizon ◽  
White Hole ◽  
Kerr Black Holes ◽  
The Way

The existence of the “Naked Singularity" has been shown taking the advantage of the Ring Singularity of the Kerr Black Hole and thereby making the way to manipulate the mathematics by taking the larger root of Δ as zero and thereby vanishing the ergosphere and event horizon making the way for the naked ring singularity which can be easily connected via a cylindrical wormhole and as ‘a wormhole is a black hole without an event horizon’ therefore, this cylindrical connection paved the way for the Einstein-Rosen Bridge allowing particles or null rays to travel from one universe to another ending up in a future directed Cauchy horizon while changing constantly from spatial to temporal and again spatial paving the entrance to another Kerr Black hole (which would act as a white hole) in the other universes.

scholarly journals Rotating spacetime: black-bounces and quantum deformed black hole

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Zhaoyi Xu ◽  
Meirong Tang
Keyword(s):  
Black Hole ◽  
Field Equation ◽  
Exact Solutions ◽  
Event Horizon ◽  
Energy Condition ◽  
Limit Surface ◽  
Schwarzschild Spacetime ◽  
Schwarzschild Metric ◽  
Link Type

AbstractRecently, two kinds of deformed schwarzschild spacetime have been proposed, which are the black-bounces metric (Simpson and Visser in J Cosmol Astropart Phys 2019:042, 2019, Lobo et al. in Phys Rev D 103:084052, 2021) and quantum deformed black hole (BH) (Berry et al. in arXiv:2102.02471, 2021). In present work, we investigate the rotating spacetime of these deformed Schwarzschild metric. They are exact solutions to the Einstein’s field equation. We analyzed the properties of these rotating spacetimes, such as event horizon (EH), stationary limit surface (SIS), structure of singularity ring, energy condition (EC), etc., and found that these rotating spacetime have some novel properties.

scholarly journals Kerr Black Holes within a Modified Theory of Gravity

Universe ◽  
2019 ◽  
Vol 5 (9) ◽  
pp. 191 ◽  
Author(s):  
Peter O. Hess ◽  
Enrique López-Moreno
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Kerr Black Hole ◽  
Standard Theory ◽  
Vacuum Fluctuations ◽  
Modified Theory Of Gravity ◽  
Theory Of Gravity ◽  
Modified Theory ◽  
Light Ring

The Kerr black hole is studied within a modified theory of gravity, which adds the effects of vacuum fluctuations near a black hole. These vacuum fluctuations are treated as a dark energy. A parameter is introduced to account for these fluctuations. It is zero for the standard theory and acquires a maximal value, just before there would be no event horizon. The existence of an event horizon not only depends on the value of this parameter, but also on the spin of the black hole. In addition, we study the existence of a light-ring. We also elaborate on the relation of the appearance and vanishing of the event horizon and light-ring to phase transitions.

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