scholarly journals PSEUDO-COMPLEX GENERAL RELATIVITY: SCHWARZSCHILD, REISSNER–NORDSTRÖM AND KERR SOLUTIONS

2012 ◽  
Vol 21 (02) ◽  
pp. 1250015 ◽  
Author(s):  
GUNTHER CASPAR ◽  
THOMAS SCHÖNENBACH ◽  
PETER OTTO HESS ◽  
MIRKO SCHÄFER ◽  
WALTER GREINER
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Dark Energy ◽  
Experimental Verification ◽  
Circular Orbit ◽  
Large Mass ◽  
Schwarzschild Solution ◽  
Energy Part ◽  
Complex General Relativity

The pseudo-complex General Relativity (pc-GR) is further considered. A new projection method is proposed. It is shown that the pc-GR introduces automatically terms into the system which can be interpreted as dark energy. The modified pseudo-complex Schwarzschild solution is investigated. The dark energy part is treated as a liquid and possible solutions are discussed. As a consequence, the collapse of a large stellar mass into a singularity at r = 0 is avoided and no event-horizon is formed. Thus, black holes do not exist. The resulting object can be viewed as a gray star. It contains no singularity which emphasizes, again, that it is not a black hole. The corrections implied by a charged large mass object (Reissner–Nordström) and a rotating gray star (Kerr) are presented. For the latter, a special solution is presented. Finally, we will consider the orbital speed of a mass in a circular orbit and suggest a possible experimental verification.

THERE ARE NO BLACK HOLES — PSEUDO-COMPLEX GENERAL RELATIVITY: REVIEW AND SOME PREDICTIONS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1217-1232 ◽  
Author(s):  
P. O. HESS ◽  
L. MAGHLAOUI ◽  
W. GREINER
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Dark Energy ◽  
Large Mass ◽  
Central Mass ◽  
Perihelion Shift ◽  
Complex Extension ◽  
Special Case ◽  
Complex General Relativity ◽  
Mass Concentrations

The pseudo-complex extension of general relativity will be reviewed, and as a special case the pseudo-complex Schwarzschild metric will be discussed. As a consequence of the pseudo-complex extension, dark energy which accumulates around central mass concentrations arises. The collapse of a large mass will be avoided due to the presence of dark energy. Some experimental consequences will be discussed, like the redshift around large mass concentrations and the perihelion shift of Mercury.

Black hole fusion made easy

2016 ◽  
Vol 25 (12) ◽  
pp. 1644015
Author(s):  
Roberto Emparan ◽  
Marina Martínez
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Event Horizon ◽  
Critical Behavior ◽  
Equivalence Principle ◽  
The Other ◽  
Schwarzschild Solution ◽  
Null Geodesics ◽  
Light Rays

The fusion of two black holes — a signature phenomenon of General Relativity — is usually regarded as a process so complex that nothing short of a supercomputer simulation can accurately capture it. In this essay, we explain how the event horizon of the merger can be found in an exact analytic way in the limit where one of the black holes is much smaller than the other. Remarkably, the ideas and techniques involved are elementary: the equivalence principle, null geodesics in the Schwarzschild solution, and the notion of event horizon itself. With these, one can identify features such as the line of caustics at which light rays enter the horizon, and find indications of universal critical behavior when the two black holes touch.

scholarly journals A Review on Black hole solutions in General Relativity

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Monika Sati ◽  
K.C. Petwal
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Field Equation ◽  
Einstein Field Equation ◽  
Schwarzschild Solution ◽  
Penrose Diagram ◽  
Static Solutions ◽  
Spherical Mass ◽  
Black Hole Solutions

In the present manuscript, we endeavour to review and develop the black hole solutions in general relativity. We emphasize here the Schwarzschild solution in Einstein’s field equation, which describes the gravitational field outside a spherical mass. The paper aims to obtain certain results, including the description of the Einstein field equation with stationary and static solutions and components of the metric that turns out to be time independent, some experiments on the Schwarzschild - Penrose diagram, the Kerr-Newman solution for rotating black holes, and the Reissner- Nordstrom solution for static and charged black holes.

scholarly journals Driven black holes: from Kolmogorov scaling to turbulent wakes

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Tomas Andrade ◽  
Christiana Pantelidou ◽  
Julian Sonner ◽  
Benjamin Withers
Keyword(s):  
Nonlinear Dynamics ◽  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Strong Field ◽  
De Sitter ◽  
Event Horizons ◽  
Binary Mergers ◽  
Tidal Deformations ◽  
Proof Of Principle

Abstract General relativity governs the nonlinear dynamics of spacetime, including black holes and their event horizons. We demonstrate that forced black hole horizons exhibit statistically steady turbulent spacetime dynamics consistent with Kolmogorov’s theory of 1941. As a proof of principle we focus on black holes in asymptotically anti-de Sitter spacetimes in a large number of dimensions, where greater analytic control is gained. We focus on cases where the effective horizon dynamics is restricted to 2+1 dimensions. We also demonstrate that tidal deformations of the horizon induce turbulent dynamics. When set in motion relative to the horizon a deformation develops a turbulent spacetime wake, indicating that turbulent spacetime dynamics may play a role in binary mergers and other strong-field phenomena.

Black Holes or Gray Stars? That’s the Question: Pseudo-Complex General Relativity

2013 ◽  
pp. 313-321
Author(s):  
Peter O. Hess ◽  
W. Greiner ◽  
T. Schönenbach ◽  
G. Caspar
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Complex General Relativity

scholarly journals Lyapunov exponent, ISCO and Kolmogorov–Senai entropy for Kerr–Kiselev black hole

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Monimala Mondal ◽  
Farook Rahaman ◽  
Ksh. Newton Singh
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Lyapunov Exponent ◽  
Circular Orbit ◽  
Real Root ◽  
Angular Frequency ◽  
Geodesic Motion ◽  
Radial Equation ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit

AbstractGeodesic motion has significant characteristics of space-time. We calculate the principle Lyapunov exponent (LE), which is the inverse of the instability timescale associated with this geodesics and Kolmogorov–Senai (KS) entropy for our rotating Kerr–Kiselev (KK) black hole. We have investigate the existence of stable/unstable equatorial circular orbits via LE and KS entropy for time-like and null circular geodesics. We have shown that both LE and KS entropy can be written in terms of the radial equation of innermost stable circular orbit (ISCO) for time-like circular orbit. Also, we computed the equation marginally bound circular orbit, which gives the radius (smallest real root) of marginally bound circular orbit (MBCO). We found that the null circular geodesics has larger angular frequency than time-like circular geodesics ($$Q_o > Q_{\sigma }$$ Q o > Q σ ). Thus, null-circular geodesics provides the fastest way to circulate KK black holes. Further, it is also to be noted that null circular geodesics has shortest orbital period $$(T_{photon}< T_{ISCO})$$ ( T photon < T ISCO ) among the all possible circular geodesics. Even null circular geodesics traverses fastest than any stable time-like circular geodesics other than the ISCO.

scholarly journals Mimicking Black Holes in General Relativity

2021 ◽  
Author(s):  
Thomas Berry
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Thin Shell ◽  
Classical General Relativity ◽  
Regular Black Hole ◽  
Regular Black Holes ◽  
Traversable Wormholes ◽  
Hole Model ◽  
Linearised Stability

<p><b>The central theme of this thesis is the study and analysis of black hole mimickers. The concept of a black hole mimicker is introduced, and various mimicker spacetime models are examined within the framework of classical general relativity. The mimickers examined fall into the classes of regular black holes and traversable wormholes under spherical symmetry. The regular black holes examined can be further categorised as static spacetimes, however the traversable wormhole is allowed to have a dynamic (non-static) throat. Astrophysical observables are calculated for a recently proposed regular black hole model containing an exponential suppression of the Misner-Sharp quasi-local mass. This same regular black hole model is then used to construct a wormhole via the "cut-and-paste" technique. The resulting wormhole is then analysed within the Darmois-Israel thin-shell formalism, and a linearised stability analysis of the (dynamic) wormhole throat is undertaken. Yet another regular black hole model spacetime is proposed, extending a previous work which attempted to construct a regular black hole through a quantum "deformation" of the Schwarzschild spacetime. The resulting spacetime is again analysed within the framework of classical general relativity. </b></p><p>In addition to the study of black hole mimickers, I start with a brief overview of the theory of special relativity where a new and novel result is presented for the combination of relativistic velocities in general directions using quaternions. This is succeed by an introduction to concepts in differential geometry needed for the successive introduction to the theory of general relativity. A thorough discussion of the concept of spacetime singularities is then provided, before analysing the specific black hole mimickers discussed above.</p>

scholarly journals HOLLOWGRAPHY DRIVEN HOLOGRAPHY: BLACK HOLE WITH VANISHING VOLUME INTERIOR

2010 ◽  
Vol 19 (14) ◽  
pp. 2345-2351 ◽  
Author(s):  
AHARON DAVIDSON ◽  
ILYA GURWICH
Keyword(s):  
Phase Transition ◽  
General Relativity ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Schwarzschild Solution ◽  
Entropy Formula ◽  
Gravitational Theories ◽  
Hollow Interior ◽  
Spatial Volume ◽  
Self Similar

Hawking–Bekenstein entropy formula seems to tell us that no quantum degrees of freedom can reside in the interior of a black hole. We suggest that this is a consequence of the fact that the volume of any interior sphere of finite surface area simply vanishes. Obviously, this is not the case in general relativity. However, we show that such a phenomenon does occur in various gravitational theories which admit a spontaneously induced general relativity. In such theories, due to a phase transition (one-parameter family degenerates) which takes place precisely at the would-have-been horizon, the recovered exterior Schwarzschild solution connects, by means of a self-similar transition profile, with a novel "hollow" interior exhibiting a vanishing spatial volume and a locally varying Newton constant. This constitutes the so-called "hollowgraphy" driven holography.

Frontiers of Quantum Black Holes

2020 ◽  
Vol 29 (11) ◽  
pp. 10-16
Author(s):  
Wontae KIM ◽  
Mu-In PARK
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Direct Detection ◽  
Occupation Number ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Quantum Radiation ◽  
Points Of View ◽  
Massless Quantum

A black hole is a theoretical prediction of Einstein’s general theory of relativity, differently from Newtonian gravity, which is a non-relativistic gravity. In recent few years, its direct detection via gravitational waves and other multi-messenger observations have made it possible to test the prediction and hence its associated general relativity. From purely theoretical points of view, general relativity cannot be a complete description due to its not being compatible with quantum mechanics, which is a successful description of microscopic objects. In this article, we introduce the conceptional development of quantum-gravity theories and give brief sketches of fundamental problems in quantum black holes. As an interesting model of quantum black holes, we consider a collapsing shell of matter to form a Hayward black hole and investigate semiclassically quantum radiation from the shell. By using the Israel’s formulation and the functional Schrödinger formulation for massless quantum radiation, we find that the Hawking temperature can be deduced from the occupation number of excited states when the shell approaches its own horizon.

Using Lorentz Violation for Early Universe GW Generation Due to Black Hole Destruction in the Early Universe as by Freeze

2021 ◽  
Author(s):  
Andrew W Beckwith
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Energy ◽  
Early Universe ◽  
Physical Mechanism ◽  
Lorentz Violation ◽  
Graviton Mass ◽  
Work Done ◽  
Momentum Relation

We are using information from a paper deriving a Lorentz-violating energy-momentum relation entailing an exact mo_mentum cutof as stated by G. Salesi . Salesi in his work allegedly defines Pre Planckian physics, whereas we restrict our given application to GW generation and DE formation in the first 10^-39s to 10^-33s or so seconds in the early universe. This procedure is inacted due to an earlier work whereas referees exhibited puzzlement as to the physical mechanism for release of Gravitons in the very early universe. The calculation is meant to be complementary to work done in the Book &ldquo;Dark Energy&rdquo; by M. Li, X-D. Li, and Y. Wang, and also a calculation for Black hole destruction as outlined by Karen Freeze, et. al. The GW generation will be when there is sufficient early universe density so as to break apart Relic Black holes but we claim that this destruction is directly linked to a Lorentz violating energy-momentum G. Salesi derived, which we adopt, with a mass m added in the G. Salesi energy momentum results proportional to a tiny graviton mass, times the number of gravitons in the first 10^-43 seconds

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