scholarly journals Light from Schwarzschild black holes in de Sitter expanding universe

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Ion I. Cotăescu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Moving Frame ◽  
Conserved Quantities ◽  
Expanding Universe ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Peculiar Velocities ◽  
Algebraic Code ◽  
Maple Code

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).

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

2021 ◽  
pp. 2150162
Author(s):  
Ion I. Cotăescu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Expanding Universe ◽  
De Sitter ◽  
Principal Parameter ◽  
Null Geodesics ◽  
Charged Black Holes ◽  
Peculiar Velocities ◽  
First Time

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.

scholarly journals VOROS PRODUCT AND NONCOMMUTATIVE INSPIRED BLACK HOLES

2013 ◽  
Vol 28 (09) ◽  
pp. 1350030
Author(s):  
SUNANDAN GANGOPADHYAY
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Extremal Point ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Standard Identity ◽  
Schwarzschild Geometry ◽  
Area Law

We emphasize the importance of the Voros product in defining the noncommutative (NC) inspired black holes. The computation of entropy for both the noncommutative inspired Schwarzschild and Reissner–Nordström (RN) black holes show that the area law holds up to order [Formula: see text]. The leading correction to the entropy (computed in the tunneling formalism) is shown to be logarithmic. The Komar energy E for these black holes is then obtained and a deviation from the standard identity E = 2STH is found at the order [Formula: see text]. This deviation leads to a nonvanishing Komar energy at the extremal point TH = 0 of these black holes. The Smarr formula is finally worked out for the NC Schwarzschild black hole. Similar features also exist for a de Sitter–Schwarzschild geometry.

scholarly journals NARIAI BLACK HOLES WITH QUINTESSENCE

2013 ◽  
Vol 28 (40) ◽  
pp. 1350189 ◽  
Author(s):  
SHARMANTHIE FERNANDO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
State Parameter ◽  
The State ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Special Values ◽  
Black Hole Temperature

In this paper we study the properties of Schwarzschild black hole surrounded by quintessence matter. The main objective of the paper is to show the existence of Nariai type black hole for special values of the parameters in the theory. The Nariai black hole with the quintessence has the topology dS2 ×S2 with dS2 with a different curvature than what would be expected for the Schwarzschild–de Sitter degenerate black hole. Temperature and the entropy for the Schwarzschild–de Sitter black hole and the Schwarzschild-quintessence black hole are compared. The temperature and the curvature are computed for general values of the state parameter ω.

scholarly journals Thermodynamics of the Schwarzschild and Reissner–Nordström black holes under the Snyder–de Sitter model

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
H. Hassanabadi ◽  
E. Maghsoodi ◽  
Won Sang Chung ◽  
M. de Montigny
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Temperature Relation ◽  
Corrected Entropy ◽  
Sitter Model ◽  
De Sitter Model

AbstractThis paper examines the effects of a new form of the extended generalized uncertainty principle in the Snyder–de Sitter model on the thermodynamics of the Schwarzschild and Reissner–Nordström black holes. Firstly, we present a generalization of the minimal length uncertainty relation with two deformation parameters. Then we obtain the corrected mass–temperature relation, entropy and heat capacity for Schwarzschild black hole. Also we investigate the effect of the corrected uncertainty principle on the thermodynamics of the charged black holes. Our discussion of the corrected entropy involves a heuristic analysis of a particle which is absorbed by the black hole. Finally, we compare the thermodynamics of a charged black hole with the thermodynamics of a Schwarzschild black hole and with the usual forms, that is, without corrections to the uncertainty principle.

The Free Energy for Rotating and Charged Black Holes and Banados, Teitelboim and Zanelli Black Holes

2018 ◽  
Vol 73 (11) ◽  
pp. 1061-1073 ◽  
Author(s):  
N.A. Hussein ◽  
D.A. Eisa ◽  
T.A.S. Ibrahim
Keyword(s):  
Black Holes ◽  
Heat Capacity ◽  
Black Hole ◽  
Free Energy ◽  
Quantum Correction ◽  
Kerr Black Hole ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Charged Black Holes ◽  
Thermodynamic Variables

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.

scholarly journals ON BRANE INFLATION POTENTIALS AND BLACK HOLE ATTRACTORS

2008 ◽  
Vol 17 (06) ◽  
pp. 911-920 ◽  
Author(s):  
ADIL BELHAJ ◽  
PABLO DIAZ ◽  
ANTONIO SEGUI ◽  
MOHAMED NACIRI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Parameter ◽  
Field Approximation ◽  
Large Field ◽  
Small Field ◽  
Explicit Computation ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Brane Inflation

We propose a new potential in brane inflation theory, which is given by the arctangent of the square of the scalar field. Then we perform an explicit computation for inflationary quantities. This potential has many nice features. In the small field approximation, it reproduces the chaotic and MSSM potentials. It allows one, in the large field approximation, to implement the attractor mechanism for bulk black holes where the geometry on the brane is de Sitter. In particular, we show, up to some assumptions, that the Friedman equation can be reinterpreted as a Schwarzschild black hole attractor equation for its mass parameter.

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.

scholarly journals Uptunneling to de Sitter

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
False Vacuum ◽  
De Sitter ◽  
Dimensional Theory ◽  
Hole Geometry ◽  
Horizon Geometry ◽  
Two Sides ◽  
Extremal Black Holes

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.

scholarly journals LUKEWARM BLACK HOLES IN QUADRATIC GRAVITY

2011 ◽  
Vol 26 (14) ◽  
pp. 999-1007 ◽  
Author(s):  
JERZY MATYJASEK ◽  
KATARZYNA ZWIERZCHOWSKA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Fourth Order ◽  
Spherically Symmetric ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Quadratic Gravity ◽  
De Sitter Universe ◽  
Electrically Charged

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.

scholarly journals Hawking radiation via tunneling from Born–Infeld AdS black hole

2016 ◽  
Vol 94 (12) ◽  
pp. 1369-1371 ◽  
Author(s):  
Gu-Qiang Li
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Emission Spectrum ◽  
Hawking Radiation ◽  
Emission Rate ◽  
De Sitter ◽  
Tunneling Radiation ◽  
Unitary Theory ◽  
Thermal Spectrum

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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