Dirac quasi-normal frequencies in a noncommutative black hole space–time

2019 ◽  
Vol 97 (5) ◽  
pp. 562-565
Author(s):  
Cuibai Luo ◽  
Chen Wu
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Noncommutative Geometry ◽  
Imaginary Part ◽  
Normal Modes ◽  
Space Time ◽  
Numerical Results ◽  
Schwarzschild Black Hole ◽  
Oscillation Frequencies ◽  
Noncommutative Parameter

Noncommutative geometry may be an alternative way to quantum gravity. We study the influence of the space–time noncommutative parameter on the Dirac quasi-normal modes in the noncommutative Schwarzschild black hole space–times. In comparison to the commutative Schwarzschild black hole, the numerical results show that the oscillation frequencies and magnitude of the imaginary part of the Dirac quasi-normal modes will increase. However, it is found that the influence of the space–time noncommutative parameter on the Dirac quasi-normal modes is tiny and negligible.

scholarly journals QUASI-NORMAL MODES OF SCHWARZSCHILD–ANTI-DE SITTER BLACK HOLES: ELECTROMAGNETIC AND GRAVITATIONAL PERTURBATIONS

2002 ◽  
Vol 17 (20) ◽  
pp. 2752-2752
Author(s):  
VITOR CARDOSO ◽  
JOSÉ P. S. LEMOS
Keyword(s):  
Black Hole ◽  
Imaginary Part ◽  
Normal Modes ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Small Black Hole ◽  
Conformal Field ◽  
Gravitational Perturbations ◽  
Ads Spacetime ◽  
Electromagnetic Perturbation

We studied the quasi-normal modes (QNM) of electromagnetic and gravitational perturbations of a Schwarzschild black hole in an asymptotically anti-de Sitter (AdS) spacetime, extending previous works1,2 on the subject. Some of the electromagnetic modes do not oscillate, they only decay, since they have pure imaginary frequencies. The gravitational modes show peculiar features: the odd and even gravitational perturbations no longer have the same characteristic quasinormal frequencies. There is a special mode for odd perturbations whose behavior differs completely from the usual one in scalar1 and electromagnetic perturbation in an AdS spacetime, but has a similar behavior to the Schwarzschild black hole3 in an asymptotically flat spacetime: the imaginary part of the frequency goes as [Formula: see text], where r+ is the horizon radius. We also investigated the small black hole limit showing that the imaginary part of the frequency goes as [Formula: see text]. These results are important to the AdS/CFT4 conjecture since according to it the QNMs describe the approach to equilibrium in the conformal field theory. For other geometries see5,6.

scholarly journals ASYMPTOTIC QUASINORMAL MODES OF A NONCOMMUTATIVE GEOMETRY INSPIRED SCHWARZSCHILD BLACK HOLE

2007 ◽  
Vol 22 (11) ◽  
pp. 2047-2056 ◽  
Author(s):  
PULAK RANJAN GIRI
Keyword(s):  
Black Hole ◽  
Noncommutative Geometry ◽  
Quasinormal Modes ◽  
Space Time ◽  
Hawking Temperature ◽  
Scalar Perturbation ◽  
Schwarzschild Black Hole ◽  
The Real ◽  
Quasinormal Frequency

We study the asymptotic quasinormal modes for the scalar perturbation of the noncommutative geometry inspired Schwarzschild black hole in 3+1 dimensions. We have considered M ≥ M0, which effectively correspond to a single horizon Schwarzschild black hole with correction due to noncommutativity. We have shown that for this situation the real part of the asymptotic quasinormal frequency is proportional to ln (3). The effect of noncommutativity of space–time on quasinormal frequency arises through the constant of proportionality, which is Hawking temperature TH(θ). We also consider the two-horizons case and show that in this case also the real part of the asymptotic quasinormal frequency is proportional to ln (3).

scholarly journals Null geodesics and red–blue shifts of photons emitted from geodesic particles around a noncommutative black hole space–time

2018 ◽  
Vol 33 (16) ◽  
pp. 1850098 ◽  
Author(s):  
Ravi Shankar Kuniyal ◽  
Rashmi Uniyal ◽  
Anindya Biswas ◽  
Hemwati Nandan ◽  
K. D. Purohit
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Noncommutative Geometry ◽  
Equatorial Plane ◽  
Mass Parameter ◽  
Space Time ◽  
Geodesic Motion ◽  
Schwarzschild Black Hole ◽  
Gravitational Fields ◽  
Test Particles

We investigate the geodesic motion of massless test particles in the background of a noncommutative geometry-inspired Schwarzschild black hole. The behavior of effective potential is analyzed in the equatorial plane and the possible motions of massless particles (i.e. photons) for different values of impact parameter are discussed accordingly. We have also calculated the frequency shift of photons in this space–time. Further, the mass parameter of a noncommutative inspired Schwarzschild black hole is computed in terms of the measurable redshift of photons emitted by massive particles moving along circular geodesics in equatorial plane. The strength of gravitational fields of noncommutative geometry-inspired Schwarzschild black hole and usual Schwarzschild black hole in General Relativity is also compared.

scholarly journals Black hole S-matrix for a scalar field

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Panos Betzios ◽  
Nava Gaddam ◽  
Olga Papadoulaki
Keyword(s):  
Black Hole ◽  
Normal Modes ◽  
Massless Scalar ◽  
Scattering Process ◽  
Schwarzschild Black Hole ◽  
Asymptotically Flat ◽  
Scalar Particles ◽  
Black Hole Background ◽  
S Matrix ◽  
Do So

Abstract We describe a unitary scattering process, as observed from spatial infinity, of massless scalar particles on an asymptotically flat Schwarzschild black hole background. In order to do so, we split the problem in two different regimes governing the dynamics of the scattering process. The first describes the evolution of the modes in the region away from the horizon and can be analysed in terms of the effective Regge-Wheeler potential. In the near horizon region, where the Regge-Wheeler potential becomes insignificant, the WKB geometric optics approximation of Hawking’s is replaced by the near-horizon gravitational scattering matrix that captures non-perturbative soft graviton exchanges near the horizon. We perform an appropriate matching for the scattering solutions of these two dynamical problems and compute the resulting Bogoliubov relations, that combines both dynamics. This allows us to formulate an S-matrix for the scattering process that is manifestly unitary. We discuss the analogue of the (quasi)-normal modes in this setup and the emergence of gravitational echoes that follow an original burst of radiation as the excited black hole relaxes to equilibrium.

scholarly journals BLACK HOLE EVAPORATION BASED UPON A q-DEFORMATION DESCRIPTION

2005 ◽  
Vol 20 (26) ◽  
pp. 6039-6049 ◽  
Author(s):  
XIN ZHANG
Keyword(s):  
Black Hole ◽  
Degrees Of Freedom ◽  
Radiation Spectrum ◽  
Correlation Effect ◽  
Space Time ◽  
Noncommutative Space ◽  
Schwarzschild Black Hole ◽  
Black Hole Evaporation ◽  
Starting Point ◽  
New Distribution

A toy model based upon the q-deformation description for studying the radiation spectrum of black hole is proposed. The starting point is to make an attempt to consider the space–time noncommutativity in the vicinity of black hole horizon. We use a trick that all the space–time noncommutative effects are ascribed to the modification of the behavior of the radiation field of black hole and a kind of q-deformed degrees of freedom are postulated to mimic the radiation particles that live on the noncommutative space–time, meanwhile the background metric is preserved as usual. We calculate the radiation spectrum of Schwarzschild black hole in this framework. The new distribution deviates from the standard thermal spectrum evidently. The result indicates that some correlation effect will be introduced to the system if the noncommutativity is taken into account. In addition, an infrared cutoff of the spectrum is the prediction of the model.

Entropy in a d-dimensional charged black hole

2018 ◽  
Vol 33 (27) ◽  
pp. 1850159 ◽  
Author(s):  
Shad Ali ◽  
Xin-Yang Wang ◽  
Wen-Biao Liu
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Hawking Radiation ◽  
Space Time ◽  
Charged Black Hole ◽  
Schwarzschild Black Hole ◽  
Proportionality Coefficient ◽  
Proportional Relation ◽  
Hamiltonian Analysis ◽  
Interior Volume

Christodoulou and Rovelli have shown that the interior volume of a Schwarzschild black hole grows linearly with time. The entropy of a scalar field in this interior volume of a Schwarzschild black hole has been calculated and shown to increase linearly with the advanced time too. In this paper, considering Hawking radiation from a d-dimensional charged black hole, we investigate the proportional relation between the entropy of the scalar field in the interior volume and the Bekenstein–Hawking entropy using the method of our previous work. We also derive this proportionality relation using Hamiltonian analysis and find a consistent result. We then investigate the proportionality coefficient with respect to d and find that it gradually decreases as the dimension of space–time increases.

Effect of post-Newtonian-like self-energy, quantum gravity and exchange correlations on Schwarzschild black hole: Application of uncertainty principle

2020 ◽  
Vol 35 (11) ◽  
pp. 2050081
Author(s):  
Baljeet Kaur Lotte ◽  
Subodha Mishra
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Correlation Energy ◽  
Particle System ◽  
Gravitational Interaction ◽  
Schwarzschild Black Hole ◽  
Loop Contribution ◽  
Exchange Correlation ◽  
Self Energy ◽  
Energy Quantum

The expressions for the corrected radius and the Hawking temperature of a Schwarzschild black hole are derived by calculating the total energy of a self-gravitating system of N fermions when the corrections to gravitational interaction due to post-Newtonian-like self-energy due to two graviton exchange- and one-loop contribution of quantum gravity effect are included. Since the particles are fermions, the exchange-correlation energy is also included consistently. It is found that though the three corrections are small, the correction due to the exchange-correlation is much more than the other two. The configuration of the many-particle system that we study is possible since it has no Buchdahl limit in the post-Newtonian approximation.

scholarly journals WHAT IS THE TOPOLOGY OF A SCHWARZSCHILD BLACK HOLE?

2012 ◽  
Vol 18 ◽  
pp. 125-129 ◽  
Author(s):  
EDMUNDO M. MONTE
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Space Time ◽  
Higher Dimension ◽  
Schwarzschild Black Hole

We investigate the topology of Schwarzschild's black holes through the immersion of this space-time in space of higher dimension. Through the immersions of Kasner and Fronsdal we calculate the extension of the Schwarzschilds black hole.

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