scholarly journals Dirac quasinormal modes in spherically symmetric regular black holes

2013 ◽  
Vol 88 (6) ◽  
Author(s):  
Jin Li ◽  
Hong Ma ◽  
Kai Lin
Keyword(s):  
Black Holes ◽  
Quasinormal Modes ◽  
Spherically Symmetric ◽  
Regular Black Holes

scholarly journals Quasinormal modes of dilatonic Reissner–Nordström black holes

2019 ◽  
Vol 79 (12) ◽  
Author(s):  
Jose Luis Blázquez-Salcedo ◽  
Sarah Kahlen ◽  
Jutta Kunz
Keyword(s):  
Black Holes ◽  
Quantitative Analysis ◽  
Electric Charge ◽  
Quasinormal Modes ◽  
Spherically Symmetric ◽  
Coupling Constant ◽  
Dilaton Coupling

AbstractWe calculate the quasinormal modes of static spherically symmetric dilatonic Reissner–Nordström black holes for general values of the electric charge and of the dilaton coupling constant. The spectrum of quasinormal modes is composed of five families of modes: polar and axial gravitational-led modes, polar and axial electromagnetic-led modes, and polar scalar-led modes. We make a quantitative analysis of the spectrum, revealing its dependence on the electric charge and on the dilaton coupling constant. For large electric charge and large dilaton coupling, strong deviations from the Reissner–Nordström modes arise. In particular, isospectrality is strongly broken, both for the electromagnetic-led and the gravitational-led modes, for large values of the charge.

scholarly journals Quasinormal modes of test fields around regular black holes

2015 ◽  
Vol 91 (8) ◽  
Author(s):  
Bobir Toshmatov ◽  
Ahmadjon Abdujabbarov ◽  
Zdeněk Stuchlík ◽  
Bobomurat Ahmedov
Keyword(s):  
Black Holes ◽  
Quasinormal Modes ◽  
Regular Black Holes

scholarly journals Asymptotic quasinormal modes of string-theoretical d-dimensional black holes

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Filipe Moura ◽  
João Rodrigues
Keyword(s):  
Differential Equation ◽  
Black Holes ◽  
Complex Plane ◽  
Quasinormal Modes ◽  
Scalar Fields ◽  
Einstein Gravity ◽  
Quasinormal Mode ◽  
Spherically Symmetric ◽  
Gravitational Perturbations

Abstract We compute the quasinormal frequencies of d-dimensional spherically symmetric black holes with leading string α′ corrections for tensorial gravitational perturbations in the highly damped regime. We solve perturbatively the master differential equation and we compute the monodromies of the master perturbation variable (analytically continued to the complex plane) in different contours, in order to obtain the quasinormal mode spectra. We proceed analogously for the quasinormal modes of test scalar fields. Differently than in Einstein gravity, we obtain distinct results for the two cases.

scholarly journals Scalar Perturbations of Black Holes in the f(R)=R−2αR Model

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 47
Author(s):  
Ping Li ◽  
Rui Jiang ◽  
Jian Lv ◽  
Xianghua Zhai
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Critical Frequency ◽  
Amplification Factor ◽  
Quasinormal Modes ◽  
Spherically Symmetric ◽  
Third Order ◽  
Charged Scalar ◽  
The Time Domain

In this paper, we study the perturbations of the charged static spherically symmetric black holes in the f(R)=R−2αR model by a scalar field. We analyze the quasinormal modes spectrum, superradiant modes, and superradiant instability of the black holes. The frequency of the quasinormal modes is calculated in the frequency domain by the third-order WKB method, and in the time domain by the finite difference method. The results by the two methods are consistent and show that the black hole stabilizes quicker for larger α satisfying the horizon condition. We then analyze the superradiant modes when the massive charged scalar field is scattered by the black hole. The frequency of the superradiant wave satisfies ω∈(μ2,ωc), where μ is the mass of the scalar field, and ωc is the critical frequency of the superradiance. The amplification factor is also calculated by numerical method. Furthermore, the superradiant instability of the black hole is studied analytically, and the results show that there is no superradiant instability for such a system.

scholarly journals Quasinormal modes of scalar and Dirac perturbations of Bardeen de Sitter black holes

2017 ◽  
Vol 26 (14) ◽  
pp. 1750160 ◽  
Author(s):  
Wadbor Wahlang ◽  
Piyush A. Jeena ◽  
Sayan Chakrabarti
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quasinormal Modes ◽  
Theory Of Relativity ◽  
De Sitter ◽  
Massive Scalar Field ◽  
Regular Black Holes ◽  
New Class ◽  
Different Types ◽  
External Form

So far the study of black hole perturbations has been mostly focused upon the classical black holes with singularities at the origin and hidden by event horizon. Compared to that, the regular black holes are a completely new class of solutions arising out of modification of general theory of relativity by coupling gravity to an external form of matter. Therefore it is extremely important to study the behavior of such regular black holes under different types of perturbations. Recently a new regular Bardeen black hole solution with a de Sitter branch has been proposed by Fernando [ arXiv:1611.05337 [gr-qc]]. We compute the quasi-normal (QN) frequencies for the regular Bardeen de Sitter (BdS) black hole due to massless and massive scalar field perturbations as well as the massless Dirac perturbations. We analyze the behavior of both real and imaginary parts of QN frequencies by varying different parameters of the theory.

scholarly journals Nonpolynomial Lagrangian approach to regular black holes

2018 ◽  
Vol 27 (03) ◽  
pp. 1830002 ◽  
Author(s):  
Aimeric Colléaux ◽  
Stefano Chinaglia ◽  
Sergio Zerbini
Keyword(s):  
Black Holes ◽  
Special Property ◽  
Nonlinear Electrodynamics ◽  
Spherically Symmetric ◽  
Density Profiles ◽  
Regular Black Holes ◽  
Curvature Invariants ◽  
Symmetric Spacetimes ◽  
Central Singularity ◽  
Spherically Symmetric Spacetimes

We present a review on Lagrangian models admitting spherically symmetric regular black holes (RBHs), and cosmological bounce solutions. Nonlinear electrodynamics, nonpolynomial gravity, and fluid approaches are explained in details. They consist respectively in a gauge invariant generalization of the Maxwell–Lagrangian, in modifications of the Einstein–Hilbert action via nonpolynomial curvature invariants, and finally in the reconstruction of density profiles able to cure the central singularity of black holes. The nonpolynomial gravity curvature invariants have the special property to be second-order and polynomial in the metric field, in spherically symmetric spacetimes. Along the way, other models and results are discussed, and some general properties that RBHs should satisfy are mentioned. A covariant Sakharov criterion for the absence of singularities in dynamical spherically symmetric spacetimes is also proposed and checked for some examples of such regular metric fields.

scholarly journals On Quasinormal Modes for Scalar Perturbations of Static Spherically Symmetric Black Holes in Nash Embedding Framework

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Sergio C. Ulhoa ◽  
Ronni G. G. Amorim ◽  
Abraão J. S. Capistrano
Keyword(s):  
Black Holes ◽  
Quasinormal Modes ◽  
Wkb Approximation ◽  
Spherically Symmetric ◽  
Third Order ◽  
Five Dimensions ◽  
The Third ◽  
Bulk Space ◽  
Scalar Perturbations

In this paper we investigate scalar perturbations of black holes embedded in a five-dimensional bulk space. The quasinormal frequencies of such black holes are calculated using the third order of Wentzel, Kramers, and Brillouin (WKB) approximation for scalar perturbations. The high overtones of quasinormal modes indicate a resonant-like set of black holes suggesting a serious constraint of embedding models in five dimensions.

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