scholarly journals Light from Reissner–Nordstrom–de Sitter black holes

2021 ◽  
pp. 2150162
Author(s):  
Ion I. Cotăescu

We derive for the first time the form of the spiral null geodesics around the photon sphere of the Reissner–Nordstrom black hole in the de Sitter expanding universe. Moreover, we obtain the principal parameter we need for deriving, according to our method [I. I. Cotăescu, Eur. Phys. J. C 81, 32 (2021)], the black hole shadow and the related redshift as measured by a remote observer situated in the asymptotic zone. We obtain thus a criterion of detecting charged black holes without peculiar velocities when one knows the mass, redshift and the black hole shadow.

Author(s):  
Ion I. Cotăescu

AbstractA new method is applied for deriving simultaneously the redshift and shadow of a Schwarzschild black hole moving freely in the de Sitter expanding universe as recorded by a remote co-moving observer. This method is mainly algebraic, focusing on the transformation of the conserved quantities under the de Sitter isometry relating the black hole co-moving frame to observer’s one. Hereby one extracts the general expressions of the redshifts and shadows of the black holes having peculiar velocities but their expressions are too extended to be written down here. Therefore, only some particular cases and intuitive expansions are presented while the complete results are given in an algebraic code (Cotăescu in Maple code BH01, https://physics.uvt.ro/~cota/CCFT/codes, 2020).


2011 ◽  
Vol 26 (39) ◽  
pp. 2923-2950 ◽  
Author(s):  
MARCO OLIVARES ◽  
JOEL SAAVEDRA ◽  
CARLOS LEIVA ◽  
JOSÉ R. VILLANUEVA

We study the motion of relativistic, electrically charged point particles in the background of charged black holes with nontrivial asymptotic behavior. We compute the exact trajectories of massive particles and express them in terms of elliptic Jacobi functions. As a result, we obtain a detailed description of particles orbits in the gravitational field of Reissner–Nordström (anti)-de Sitter black hole, depending of their charge, mass and energy.


2018 ◽  
Vol 73 (11) ◽  
pp. 1061-1073 ◽  
Author(s):  
N.A. Hussein ◽  
D.A. Eisa ◽  
T.A.S. Ibrahim

AbstractThis paper aims to obtain the thermodynamic variables (temperature, thermodynamic volume, angular velocity, electrostatic potential, and heat capacity) corresponding to the Schwarzschild black hole, Reissner-Nordstrom black hole, Kerr black hole and Kerr-Newman-Anti-de Sitter black hole. We also obtained the free energy for black holes by using three different methods. We obtained the equation of state for rotating Banados, Teitelboim and Zanelli black holes. Finally, we used the quantum correction of the partition function to obtain the heat capacity and entropy in the quantum sense.


2005 ◽  
Vol 14 (08) ◽  
pp. 1373-1412 ◽  
Author(s):  
NG. IBOHAL ◽  
L. DORENDRO

In this paper we derive a class of non-stationary rotating solutions including Vaidya–Bonnor–de Sitter, Vaidya–Bonnor-monopole and Vaidya–Bonnor–Kerr. The rotating Viadya–Bonnor–de Sitter solution describes an embedded black hole that the rotating Vaidya–Bonnor black hole is embedded into the rotating de Sitter cosmological universe. In the case of the Vaidya–Bonnor–Kerr, the rotating Vaidya–Bonnor solution is embedded into the vacuum Kerr solution, and similarly, Vaidya–Bonnor-monopole. By considering the charge to be function of u and r, we discuss the Hawking's evaporation of the masses of variable-charged non-embedded, non-rotating and rotating Vaidya–Bonnor, and embedded rotating, Vaidya–Bonnor–de Sitter, Vaidya–Bonnor-monopole and Vaidya–Bonnor–Kerr, black holes. It is found that every electrical radiation of variable-charged black holes will produce a change in the mass of the body without affecting the Maxwell scalar in non-embedded cases; whereas in embedded cases, the Maxwell scalar, the cosmological constant, monopole charge and the Kerr mass are not affected by the radiation process. It was also found that during the Hawking's radiation process, after the complete evaporation of masses of these variable-charged black holes, the electrical radiation will continue creating (i) negative mass naked singularities in non-embedded ones, and (ii) embedded negative mass naked singularities in embedded black holes. The surface gravity, entropy and angular velocity of the horizon are presented for each of these non-stationary black holes.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Sharmanthie Fernando

We present interesting properties of null geodesics of static charged black holes in Einstein-Born-Infeld gravity. These null geodesics represents the path for gravitons. In addition, we also study the path of photons for the Born-Infeld black hole which are null geodesics of an effective geometry. We will present how the bending of light is effected by the non-linear parameter of the theory. Some other properties, such as the horizon radius and the temperature are also discussed in the context of the nonlinear parameter .


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Tomas Andrade ◽  
Christiana Pantelidou ◽  
Julian Sonner ◽  
Benjamin Withers

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.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi

Abstract We propose a Euclidean preparation of an asymptotically AdS2 spacetime that contains an inflating dS2 bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS2 approximates the near horizon geometry of a two-sided near-extremal Reissner-Nordström black hole, and the two sides can connect to the same Minkowski asymptotics to form a topologically nontrivial worm- hole geometry. Likewise, in the false vacuum the near-horizon geometry of near-extremal black holes is approximately dS2 times 2-sphere. We interpret the Euclidean solution as describing the decay of an excitation inside the wormhole to a false vacuum bubble. The result is an inflating region inside a non-traversable asymptotically Minkowski wormhole.


2004 ◽  
Vol 13 (07) ◽  
pp. 1375-1379 ◽  
Author(s):  
MANUEL MALHEIRO ◽  
RODRIGO PICANÇO ◽  
SUBHARTHI RAY ◽  
JOSÉ P. S. LEMOS ◽  
VILSON T. ZANCHIN

Effect of maximum amount of charge a compact star can hold, is studied here. We analyze the different features in the renewed stellar structure and discuss the reasons why such huge charge is possible inside a compact star. We studied a particular case of a polytropic equation of state (EOS) assuming the charge density is proportional to the mass density. Although the global balance of force allows a huge charge, the electric repulsion faced by each charged particle forces it to leave the star, resulting in the secondary collapse of the system to form a charged black hole.


2011 ◽  
Vol 26 (14) ◽  
pp. 999-1007 ◽  
Author(s):  
JERZY MATYJASEK ◽  
KATARZYNA ZWIERZCHOWSKA

Perturbative solutions to the fourth-order gravity describing spherically-symmetric, static and electrically charged black hole in an asymptotically de Sitter universe is constructed and discussed. Special emphasis is put on the lukewarm configurations, in which the temperature of the event horizon equals the temperature of the cosmological horizon.


2016 ◽  
Vol 94 (12) ◽  
pp. 1369-1371 ◽  
Author(s):  
Gu-Qiang Li

The tunneling radiation of particles from Born–Infeld anti-de Sitter black holes is studied by using the Parikh–Wilczek method and the emission rate of a particle is calculated. It is shown that the emission rate is related to the change of the Bekenstein–Hawking entropy of the black hole and the emission spectrum deviates from the purely thermal spectrum but is consistent with an underlying unitary theory.


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