THE SCALAR FIELD IN EXTREME REISSNER–NORDSTRÖM–DE SITTER SPACE

2003 ◽  
Vol 18 (26) ◽  
pp. 4829-4836 ◽  
Author(s):  
GUANG-HAI GUO ◽  
YUAN-XING GUI ◽  
JIAN-XIANG TIAN
Keyword(s):  
Black Hole ◽  
Field Equation ◽  
Scalar Field ◽  
Special Interest ◽  
Field Amplitude ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Tortoise Coordinate

By generalizing the method of I. Brevik et al. the scalar field equation between the outer black hole horizon and the cosmological horizon in the extreme Reissner–Nordström–de Sitter (RNdS) geometry is solved. The field amplitude, as well as the potential, is shown graphically by introducing the "tangent" approximation, which is more exact than that used by I. Brevik et al., of the tortoise coordinate. There are two limiting cases of our special interest. The first one is when the cosmological horizon is very close to the outer horizon of the "black hole." The second one is when they are far apart. And the reflection and transmission coefficients are worked out in the two cases respectively.

scholarly journals THE REAL SCALAR FIELD EQUATION FOR NARIAI BLACK HOLE IN THE 5D SCHWARZSCHILD–DE SITTER BLACK STRING SPACE

2007 ◽  
Vol 22 (24) ◽  
pp. 4451-4465 ◽  
Author(s):  
MOLIN LIU ◽  
HONGYA LIU ◽  
CHUNXIAO WANG ◽  
YONGLI PING
Keyword(s):  
Black Hole ◽  
Field Equation ◽  
Scalar Field ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
De Sitter ◽  
Black String ◽  
Transmission Coefficients ◽  
Scalar Field Equation ◽  
Continuous Potential

The Nariai black hole, whose two horizons are lying close to each other, is an extreme and important case in the research of black hole. In this paper we study the evolution of a massless scalar field scattered around in 5D Schwarzschild–de Sitter black string space. Using the method shown by Brevik and Simonsen (2001) we solve the scalar field equation as a boundary value problem, where real boundary condition is employed. Then with convenient replacement of the 5D continuous potential by square barrier, the reflection and transmission coefficients (R, T) are obtained. At last, we also compare the coefficients with the usual 4D counterpart.

THE SOLUTION OF DIRAC EQUATION IN QUASI-EXTREME REISSNER–NORDSTRÖM DE SITTER SPACE

2009 ◽  
Vol 24 (30) ◽  
pp. 2433-2443 ◽  
Author(s):  
YAN LYU ◽  
SONG CUI ◽  
LING LIU
Keyword(s):  
Dirac Equation ◽  
Inverse Function ◽  
Quantum Mechanical ◽  
De Sitter ◽  
Mechanical Method ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
First Case ◽  
Quantum Mechanical Method ◽  
Tortoise Coordinate

The radial parts of Dirac equation between the outer black hole horizon and the cosmological horizon in quasi-extreme Reissner–Nordström de Sitter (RNdS) geometry is solved numerically. We use an accurate polynomial approximation to mimic the modified tortoise coordinate [Formula: see text], for obtaining the inverse function [Formula: see text] and [Formula: see text]. We then use a quantum mechanical method to solve the wave equation and give the reflection and transmission coefficients. We concentrate on two limiting cases. The first case is when the two horizons are close to each other, and the second case is when the horizons are far apart.

scholarly journals Spacetime Entanglement Entropy of de Sitter and Black Hole Horizons

2021 ◽  
Author(s):  
Abhishek Mathur ◽  
Sumati Surya ◽  
Nomaan X
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Density Matrix ◽  
Mixed State ◽  
Entanglement Entropy ◽  
Spatial Density ◽  
De Sitter Spacetime ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Sitter Spacetime

Abstract We calculate Sorkin's manifestly covariant, spacetime entanglement entropy (SSEE) for a massive and massless minimally coupled free Gaussian scalar field for the de Sitter horizon and Schwarzschild de Sitter horizons, respectively, in d > 2. In de Sitter spacetime we restrict the Bunch-Davies vacuum in the conformal patch to the static patch to obtain a mixed state. The finiteness of the spatial L2 norm in the static patch implies that the SSEE is well defined for each mode. We find that for this mixed state it is independent of the effective mass of the scalar field and matches results obtained by Higuchi and Yamamoto, where, a spatial density matrix was used to calculate the horizon entanglement entropy. Using a cut-off in the angular modes we show that the SSEE is proportional to the area of the de Sitter cosmological horizon. Our analysis can be carried over to the black hole and cosmological horizon in Schwarzschild de Sitter spacetime, which also has finite spatial L2 norm in the static regions. Although the explicit form of the modes is not known in this case, we use appropriate boundary conditions for a massless minimally coupled scalar field, to find the mode-wise SSEE for both the black hole and de Sitter cosmological horizons. As in the de Sitter calculation we see that SSEE is proportional to the horizon area in each case after taking a cut-off in the angular modes.

scholarly journals EFFECTS OF BLACK HOLES ON INFLATON PERTURBATION

2012 ◽  
Vol 12 ◽  
pp. 272-279
Author(s):  
HING-TONG CHO ◽  
KIN-WANG NG ◽  
I-CHIN WANG
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Power Spectrum ◽  
Perturbation Approach ◽  
Inflationary Universe ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Small Black Hole ◽  
Free Scalar

We calculate quantum fluctuations of a free scalar field in the Schwarzschild-de Sitter space-time, adopting the planar coordinates that is pertinent to the presence of a black hole in an inflationary universe. In a perturbation approach, doing expansion in powers of a small black hole event horizon compared to the de Sitter cosmological horizon, we obtain the scalar power spectrum.

scholarly journals Quasi-normal modes and the area spectrum of a near extremal de Sitter black hole with conformally coupled scalar field

2015 ◽  
Vol 30 (11) ◽  
pp. 1550057 ◽  
Author(s):  
Sharmanthie Fernando
Keyword(s):  
Black Hole ◽  
Wave Equation ◽  
Scalar Field ◽  
Normal Modes ◽  
Type Equation ◽  
Area Spectrum ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
De Sitter ◽  
Quasi Normal Mode

In this paper, we have studied a black hole in de Sitter space which has a conformally coupled scalar field in the background. This black hole is also known as the MTZ black hole. We have obtained exact values for the quasi-normal mode (QNM) frequencies under massless scalar field perturbations. We have demonstrated that when the black hole is near-extremal, that the wave equation for the massless scalar field simplifies to a Schrödinger type equation with the well-known Pöschl–Teller potential. We have also used sixth-order WKB approximation to compute QNM frequencies to compare with exact values obtained via the Pöschl–Teller method for comparison. As an application, we have obtained the area spectrum using modified Hods approach and show that it is equally spaced.

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.

The entropy evolution of a Schwarzschild–(Anti) de Sitter black hole

2020 ◽  
Vol 29 (07) ◽  
pp. 2050048
Author(s):  
Xin-Yang Wang ◽  
Yi-Ru Wang ◽  
Wen-Biao Liu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Hawking Radiation ◽  
Dynamical Variable ◽  
De Sitter ◽  
The One ◽  
Definition Of ◽  
Spherically Symmetry ◽  
Interior Volume

Based on the definition of the interior volume of spherically symmetry black holes, the interior volume of Schwarzschild–(Anti) de Sitter black holes is calculated. It is shown that with the cosmological constant ([Formula: see text]) increasing, the changing behaviors of both the position of the largest hypersurface and the interior volume for the Schwarzschild–Anti de Sitter black hole are the same as the Schwarzschild–de Sitter black hole. Considering a scalar field in the interior volume and Hawking radiation with only energy, the evolution relation between the scalar field entropy and Bekenstein–Hawking entropy is constructed. The results show that the scalar field entropy is approximately proportional to Bekenstein–Hawking entropy during Hawking radiation. Meanwhile, the proportionality coefficient is also regarded as a constant approximately with the increasing [Formula: see text]. Furthermore, considering [Formula: see text] as a dynamical variable, the modified Stefan–Boltzmann law is proposed which can be used to describe the variation of both the mass and [Formula: see text] under Hawking radiation. Using this modified law, the evolution relation between the two types of entropy is also constructed. The results show that the coefficient for Schwarzschild–de Sitter black holes is closer to a constant than the one for Schwarzschild–Anti de Sitter black holes during the evaporation process. Moreover, we find that for Hawking radiation carrying only energy, the evolution relation is a special case compared with the situation that the mass and [Formula: see text] are both considered as dynamical variables.

scholarly journals Existence condition and phase transition of Reissner–Nordström–de Sitter black hole

2014 ◽  
Vol 29 (09) ◽  
pp. 1450050 ◽  
Author(s):  
Meng-Sen Ma ◽  
Hui-Hua Zhao ◽  
Li-Chun Zhang ◽  
Ren Zhao
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Thermodynamic Properties ◽  
Electric Charge ◽  
Transition Point ◽  
Existence Condition ◽  
Phase Transition Point ◽  
Black Hole Horizon ◽  
Cosmological Horizon ◽  
De Sitter

After introducing the connection between the black hole horizon and the cosmological horizon, we discuss the thermodynamic properties of Reissner–Nordström–de Sitter (RN–dS) space–time. We present the condition under which RN–dS black hole can exist. Employing Ehrenfest' classification, we conclude that the phase transition of RN–dS black hole is the second-order one. The position of the phase transition point is irrelevant to the electric charge of the system. It only depends on the ratio of the black hole horizon and the cosmological horizon.

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