scholarly journals Low energy greybody factors for fermions emitted by a Schwarzschild-de Sitter black hole

2016 ◽  
Vol 25 (04) ◽  
pp. 1650043 ◽  
Author(s):  
Ciprian A. Sporea ◽  
Andrzej Borowiec
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Energy Spectrum ◽  
Analytical Methods ◽  
Total Angular Momentum ◽  
Low Energy ◽  
De Sitter ◽  
Scalar Particles ◽  
Low Energies ◽  
Sds Black Hole

In this paper, we are discussing the problem of low energy greybody factors for fermions emitted by a Schwarzschild-de Sitter (SdS) black hole. In our study, we are using the analytical methods proposed by Unruh some time ago for determining the greybody factors. We have found that at low energies the greybody factors are constant for a given total angular momentum (similar to what happens in the case of scalar particles reported before in the literature). Also, our results are indicating an enhancement in the energy spectrum if one is increasing the value of the cosmological constant. These results are consistent with numerical calculations performed by S. F. Wu et al., Phys. Rev. D 78 (1998) 084010.

scholarly journals Quantum gravity effect on the Hawking radiation of spinning dilaton black hole

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Ganim Gecim ◽  
Yusuf Sucu
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Quantum Gravity ◽  
Total Angular Momentum ◽  
Vector Boson ◽  
Scalar Particle ◽  
Dirac Particle ◽  
Hawking Temperature ◽  
Quantum Gravity Effect ◽  
Dilaton Black Hole

Abstract The quantum gravity correction to the Hawking temperature of the 2+1 dimensional spinning dilaton black hole is studied by using the Hamilton-Jacobi approach in the context of the Generalized Uncertainty Principle (GUP). It is observed that the modified Hawking temperature of the black hole depends on both black hole and the tunnelling particle properties. Moreover, it is observed that the mass and the angular momentum of the scalar particle have the same effect on the Hawking temperature of the black hole, while the mass and total angular momentum (orbital+spin) of Dirac particle have different effect. Furthermore, the mass and total angular momentum (orbital+spin) of vector boson particle have a similar effect that of Dirac particle. Also, thermodynamical stability and phase transition of the black hole are discussed for scalar, Dirac and vector boson in the context of GUP, respectively. And, it is observed that the scalar particle probes the black hole as stable whereas, as for Dirac and vector boson particles, it might undergoes second-type phase transition to become stable while in the absence of the quantum gravity effect all of these particle probes the black hole as stable.

scholarly journals The GUP Effect on Tunneling of Massive Vector Bosons from The 2+1 Dimensional Black Hole

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Ganim Gecim ◽  
Yusuf Sucu
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Total Angular Momentum ◽  
Vector Boson ◽  
Generalized Uncertainty Principle ◽  
Hawking Temperature ◽  
Massive Vector ◽  
Vector Bosons ◽  
Dimensional Black Hole ◽  
The Stability

In this study, the Generalized Uncertainty Principle (GUP) effect on the Hawking radiation formed by tunneling of a massive vector boson particle from the 2+1 dimensional new-type black hole was investigated. We used modified massive vector boson equation based on the GUP. Then, the Hamilton-Jacobi quantum tunneling approach was used to work out the tunneling probability of the massive vector boson particle and Hawking temperature of the black hole. Due to the GUP effect, the modified Hawking temperature was found to depend on the black hole properties, on the AdS3 radius, and on the energy, mass, and total angular momentum of the tunneling massive vector boson. In the light of these results, we also observed that modified Hawking temperature increases by the total angular momentum of the particle while it decreases by the energy and mass of the particle and the graviton mass. Also, in the context of the GUP, we see that the Hawking temperature due to the tunneling massive vector boson is completely different from both that of the spin-0 scalar and that of the spin-1/2 Dirac particles obtained in the previous study. We also calculate the heat capacity of the black hole using the modified Hawking temperature and then discuss influence of the GUP on the stability of the black hole.

scholarly journals Graviatoms with de Sitter Interior

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Irina Dymnikova ◽  
Michael Fil’chenkov
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Dark Energy ◽  
Charged Particle ◽  
Energy Spectrum ◽  
Primordial Black Hole ◽  
De Sitter ◽  
Fundamental Symmetry ◽  
Gravitational Vacuum ◽  
De Sitter Vacuum

We present a graviatom with de Sitter interior as a new candidate to atomic dark matter generically related to a vacuum dark energy through its de Sitter vacuum interior. It is a gravitationally bound quantum system consisting of a nucleus represented by a regular primordial black hole (RPBH), its remnant or gravitational vacuum soliton G-lump, and a charged particle. We estimate probability of formation of RPBHs and G-lumps in the early Universe and evaluate energy spectrum and electromagnetic radiation of graviatom which can in principle bear information about a fundamental symmetry scale responsible for de Sitter interior and serve as its observational signatures.

scholarly journals Logarithmic Corrections to the FRW Brane Cosmology from 5d Schwarzschild–de Sitter Black Hole

2003 ◽  
Vol 18 (19) ◽  
pp. 3395-3416 ◽  
Author(s):  
Shin'ichi Nojiri ◽  
Sergei D. Odintsov ◽  
Sachiko Ogushi
Keyword(s):  
Black Hole ◽  
Black Hole Entropy ◽  
Slight Modification ◽  
Thermal Fluctuations ◽  
De Sitter ◽  
Brane Cosmology ◽  
Verlinde Formula ◽  
Logarithmic Corrections ◽  
Constant Change ◽  
Sds Black Hole

Thermodynamics of 5d SdS black hole is considered. Thermal fluctuations define the (sub-dominant) logarithmic corrections to black hole entropy and then to Cardy–Verlinde formula and to FRW brane cosmology. We demonstrate that logarithmic terms (which play the role of effective cosmological constant) change the behavior of 4d spherical brane in dS, SdS or Nariai bulk. In particularly, bounce Universe occurs or 4d dS brane expands to its maximum and then shrinks. The entropy bounds are also modified by next-to-leading terms. Out of braneworld context the logarithmic terms may suggest slight modification of standard FRW cosmology.

scholarly journals Hawking Non-thermal and Purely Thermal Radiations of Rotating Black Hole in Anti-de Sitter Space Time by Hamilton-Jacobi Method

2018 ◽  
Vol 37 ◽  
pp. 99-109
Author(s):  
M Ilias Hossain
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Emission Spectrum ◽  
Hawking Radiation ◽  
De Sitter Space ◽  
Space Time ◽  
Jacobi Method ◽  
De Sitter ◽  
Tunneling Method ◽  
Thermal Radiations

We have explored Hawking non-thermal and purely thermal radiations of Kerr-anti-de Sitter (KAdS) black hole using massive particles tunneling method by taking into account the space time background as dynamical, energy and angular momentum as conserved incorporating the selfgravitation effect of the emitted particles. The results we have obtained for KAdS black hole have shown that the tunneling rates are related to the change of Bekenstein-Hawking entropy and the derived emission spectrum deviates from the pure thermal spectrum and also the obtaining results for KAdS black hole are accordant with Parikh and Wilczek’s opinion and gives a correction to the Hawking radiation of KAdS black hole.GANIT J. Bangladesh Math. Soc.Vol. 37 (2017) 99-109

scholarly journals On the Schwarzschild-Anti-de Sitter black hole with an f(R) global monopole

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
H. S. Vieira
Keyword(s):  
Black Hole ◽  
Gordon Equation ◽  
Global Monopole ◽  
De Sitter ◽  
Scalar Particles ◽  
Black Hole Radiation ◽  
Effective Cosmological Constant ◽  
Klein Gordon ◽  
Physical Phenomena

AbstractIn this work, we follow the recently revisited f(R) theory of gravity for studying the interaction between quantum scalar particles and the gravitational field of a generalized black hole with an f(R) global monopole. This background has a term playing the role of an effective cosmological constant, which permits us to call it as Schwarzschild-Anti-de Sitter (SAdS) black hole with an f(R) global monopole. We examine the separability of the Klein–Gordon equation with a non-minimal coupling and then we discuss both the massless and massive cases for a conformal coupling. We investigate some physical phenomena related to the asymptotic behavior of the radial function, namely, the black hole radiation, the quasibound states, and the wave eigenfunctions.

scholarly journals Decline of the Current Quadrupole Moment during the Merger Phase of Binary Black Hole Coalescence

Universe ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 3
Author(s):  
Fan Zhang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Quadrupole Moment ◽  
Total Angular Momentum ◽  
Quasinormal Modes ◽  
Binary Black Hole ◽  
Mass Quadrupole

Utilizing the tools of tendex and vortex, we study the highly dynamic plunge and merger phases of several π -symmetric binary black hole coalescences. In particular, we observe a decline of the strength of the current quadrupole moment compared to that of the mass quadrupole moment during the merger phase, contrary to a naive estimate according to the dependence of these moments on the separation between the black holes. We further show that this decline of the current quadrupole moment is achieved through the remnants of the two individual spins becoming nearly aligned or anti-aligned with the total angular momentum. We also speculate on the ability to achieve a consistency between the electric and magnetic parity quasinormal modes.

MULTI-BLACK HOLES SOLUTION WITH COSMIC STRINGS

2004 ◽  
Vol 19 (10) ◽  
pp. 1549-1557 ◽  
Author(s):  
F. ÖZDEMIR ◽  
N. ÖZDEMIR ◽  
B. T. KAYNAK
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Cosmic String ◽  
Circular Orbit ◽  
Cosmic Strings ◽  
De Sitter ◽  
Circular Orbits ◽  
Small Oscillations ◽  
String Models

Some black hole-cosmic string models such as Reissner–Nordström, RN–de Sitter, Kerr–Newman and multi-black holes with cosmic string are given. Energy and angular momentum of a timelike particle in circular orbits in multi-black hole space–time are calculated. The geodesic equations for the timelike particles for the far region of the multi-black hole sources are calculated and small oscillations around the circular orbit obtained. It is seen that the particle's orbit precesses like the Lens–Thirring effect.

scholarly journals Thermodynamic properties of black holes in de Sitter space

2016 ◽  
Vol 32 (02) ◽  
pp. 1750017 ◽  
Author(s):  
Huai-Fan Li ◽  
Meng-Sen Ma ◽  
Ya-Qin Ma
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Heat Capacity ◽  
Black Hole ◽  
Thermodynamic Properties ◽  
Thermodynamic Quantities ◽  
De Sitter ◽  
First Law Of Thermodynamics ◽  
Effective Temperatures ◽  
Sds Black Hole

We study the thermodynamic properties of Schwarzschild–de Sitter (SdS) black hole and Reissner–Nordström–de Sitter (RNdS) black hole in view of global and effective thermodynamic quantities. Making use of the effective first law of thermodynamics, we can derive the effective thermodynamic quantities of de Sitter black holes. It is found that these effective thermodynamic quantities also satisfy Smarr-like formula. Especially, the effective temperatures are nonzero in the Nariai limit. By calculating heat capacity and Gibbs free energy, we find SdS black hole is always thermodynamically stable and RNdS black hole may undergoes phase transition at some points.

scholarly journals Dirac–Kähler particle in Riemann spherical space: boson interpretation

2015 ◽  
Vol 93 (11) ◽  
pp. 1427-1433 ◽  
Author(s):  
A.M. Ishkhanyan ◽  
O. Florea ◽  
E.M. Ovsiyuk ◽  
V.M. Red’kov
Keyword(s):  
Angular Momentum ◽  
Energy Spectrum ◽  
General Solution ◽  
Differential Equations ◽  
Hypergeometric Functions ◽  
Total Angular Momentum ◽  
Positive Curvature ◽  
Dirac Particle ◽  
Spherical Space ◽  
Discrete Energy

In the context of the composite boson interpretation, we construct the exact general solution of the Dirac–Kähler equation for the case of the spherical Riemann space of constant positive curvature, for which due to the geometry itself one may expect to have a discrete energy spectrum. In the case of the minimum value of the total angular momentum, j = 0, the radial equations are reduced to second-order ordinary differential equations, which are straightforwardly solved in terms of the hypergeometric functions. For nonzero values of the total angular momentum, however, the radial equations are reduced to a pair of complicated fourth-order differential equations. Employing the factorization approach, we derive the general solution of these equations involving four independent fundamental solutions written in terms of combinations of the hypergeometric functions. The corresponding discrete energy spectrum is then determined via termination of the involved hypergeometric series, resulting in quasi-polynomial wave-functions. The constructed solutions lead to notable observations when comparing with those for the ordinary Dirac particle. The energy spectrum for the Dirac–Kähler particle in spherical space is much more complicated. Its structure substantially differs from the one for the Dirac particle because it consists of two energy level series in parallel, each of which is twice degenerate. Besides, none of the two separate series coincides with the series for the Dirac particle. Thus, the Dirac–Kähler field cannot be interpreted as a system of four Dirac fermions. Additional arguments supporting this conclusion are discussed.

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