scholarly journals OBJECT PICTURE, QUASINORMAL MODES AND LATE TIME TAILS OF FERMION PERTURBATIONS IN STRINGY BLACK HOLES WITH U(1) CHARGES

2012 ◽  
Vol 21 (05) ◽  
pp. 1250044 ◽  
Author(s):  
OWEN PAVEL FERNÁNDEZ PIEDRA ◽  
FIDEL SOSA NUÑEZ ◽  
JOSE BERNAL CASTILLO ◽  
YULIER JIMENEZ SANTANA
Keyword(s):  
Black Holes ◽  
Present Report ◽  
Quasinormal Modes ◽  
Late Time ◽  
Massless Fermion ◽  
Time Profiles ◽  
Power Law Decay ◽  
Fermion Fields ◽  
Higher Dimensional ◽  
Boson Fields

The aim of the present report is the study of massless fermion perturbations outside five-dimensional stringy black holes with U(1) charges. The Dirac equation was numerically solved to obtain the time profiles for evolving fermion fields, and the quasinormal frequencies at intermediate times are computed by numerical Prony fitting and semi-analytical Wentzel–Kramers–Brillouin (WKB) expansion at sixth-order. We also computed numerically the latetime power law decay factors, showing that there are in correspondence with previously reported results for the case of boson fields in higher-dimensional odd spacetimes. The dependence of quasinormal frequencies with U(1) compactification charges are studied.

FERMION PERTURBATIONS IN HIGHER-DIMENSIONAL STRING-THEORY BLACK HOLES

2013 ◽  
Vol 22 (10) ◽  
pp. 1350073
Author(s):  
OWEN PAVEL FERNÁNDEZ PIEDRA ◽  
JOSE BERNAL CASTILLO ◽  
YULIER JIMENEZ SANTANA ◽  
LEOSDAN FIGUEREDO NORIS
Keyword(s):  
Black Hole ◽  
Damping Factor ◽  
Test Field ◽  
Perfect Agreement ◽  
Massless Fermion ◽  
Time Domain Data ◽  
Fermion Fields ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
The Time Domain

In this paper, we report the results of a detailed investigation of the complete time evolution of massless fermion fields propagating in spacetimes of higher-dimensional stringy black hole solutions, obtained from intersecting branes in string/M theory. We write the Dirac equation in D-dimensional spacetime in a form suitable to perform a numerical integration of it, and using a Prony fitting of the time domain data, we determine the quasinormal frequencies that characterize the test field evolution at intermediary times. We also present the results obtained for the quasinormal frequencies using a sixth-order WKB approximation, that are in perfect agreement with the numerical results. The power-law exponents that describe the field relaxation at very late-times are also determined, and we show that they depends upon the dimensionality of spacetime, and are identical to that associated with the relaxation of boson fields for odd dimensions. The dependence of the frequencies and damping factor of the spinor field with the charges of the stringy black hole are studied.

scholarly journals QUASINORMAL MODES AND LATE-TIME TAILS OF CANONICAL ACOUSTIC BLACK HOLES

2007 ◽  
Vol 16 (07) ◽  
pp. 1211-1218 ◽  
Author(s):  
PING XI ◽  
XIN-ZHOU LI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Wave Propagation ◽  
Angular Momentum ◽  
Numerical Method ◽  
Time Scale ◽  
Quasinormal Modes ◽  
Late Time ◽  
Classical Wave ◽  
Acoustic Black Holes

In this paper, we investigate the evolution of classical wave propagation in the canonical acoustic black hole by a numerical method and discuss the details of the tail phenomenon. The oscillating frequency and damping time scale both increase with the angular momentum l. For lower l, numerical results show the lowest WKB approximation gives the most reliable result. We also find that the time scale of the interim region from ringing to tail is not affected obviously by changing l.

scholarly journals Quasinormal Modes of Charged Black Holes in Higher-Dimensional Einstein-Power-Maxwell Theory

Axioms ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 33 ◽  
Author(s):  
Grigoris Panotopoulos
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Electric Charge ◽  
Quasinormal Modes ◽  
Space Time ◽  
Maxwell Theory ◽  
Charged Black Holes ◽  
Higher Dimensional ◽  
The Impact ◽  
Scalar Perturbations

We compute the quasinormal frequencies for scalar perturbations of charged black holes in five-dimensional Einstein-power-Maxwell theory. The impact on the spectrum of the electric charge of the black holes, of the angular degree, of the overtone number, and of the mass of the test scalar field is investigated in detail. The quasinormal spectra in the eikonal limit are computed as well for several different space-time dimensionalities.

scholarly journals Accelerating black holes: Quasinormal modes and late-time tails

2020 ◽  
Vol 102 (4) ◽  
Author(s):  
Kyriakos Destounis ◽  
Rodrigo D. B. Fontana ◽  
Filipe C. Mena
Keyword(s):  
Black Holes ◽  
Quasinormal Modes ◽  
Late Time

scholarly journals Dirac quasinormal modes of power-Maxwell charged black holes in Rastall gravity

2020 ◽  
Vol 35 (23) ◽  
pp. 2050193
Author(s):  
Cai-Ying Shao ◽  
Yu Hu ◽  
Yu-Jie Tan ◽  
Cheng-Gang Shao ◽  
Kai Lin ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Matrix Method ◽  
Quasinormal Modes ◽  
Einstein Gravity ◽  
Late Time ◽  
Charged Black Holes ◽  
The Matrix ◽  
Black Hole Solutions ◽  
Extremal Black Holes

In this paper, we study the quasinormal modes of the massless Dirac field for charged black holes in Rastall gravity. The spherically symmetric black hole solutions in question are characterized by the presence of a power-Maxwell field, surrounded by the quintessence fluid. The calculations are carried out by employing the WKB approximations up to the 13th-order, as well as the matrix method. The temporal evolution of the quasinormal modes is investigated by using the finite difference method. Through numerical simulations, the properties of the quasinormal frequencies are analyzed, including those for the extremal black holes. Among others, we explore the case of a second type of extremal black holes regarding the Nariai solution, where the cosmical and event horizon coincide. The results obtained by the WKB approaches are found to be mostly consistent with those by the matrix method. It is observed that the magnitudes of both real and imaginary parts of the quasinormal frequencies increase with increasing [Formula: see text], the spin–orbit quantum number. Also, the roles of the parameters [Formula: see text] and [Formula: see text], associated with the electric charge and the equation of state of the quintessence field, respectively, are investigated regarding their effects on the quasinormal frequencies. The magnitude of the electric charge is found to sensitively affect the time scale of the first stage of quasinormal oscillations, after which the temporal oscillations become stabilized. It is demonstrated that the black hole solutions for Rastall gravity in asymptotically flat spacetimes are equivalent to those in Einstein gravity, featured by different asymptotical spacetime properties. As one of its possible consequences, we also investigate the behavior of the late-time tails of quasinormal models in the present model. It is found that the asymptotical behavior of the late-time tails of quasinormal modes in Rastall theory is governed by the asymptotical properties of the spacetimes of their counterparts in Einstein gravity.

scholarly journals Late-time tails, entropy aspects, and stability of black holes with anisotropic fluids

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
B. Cuadros-Melgar ◽  
R. D. B. Fontana ◽  
Jeferson de Oliveira
Keyword(s):  
Black Holes ◽  
Causal Structure ◽  
Quasinormal Modes ◽  
Black Hole Entropy ◽  
Late Time ◽  
Time Behavior ◽  
Brick Wall ◽  
De Sitter ◽  
Four Dimensions ◽  
Anisotropic Fluids

AbstractIn this work we consider black holes surrounded by anisotropic fluids in four dimensions. We first study the causal structure of these solutions showing some similarities and differences with Reissner–Nordström–de Sitter black holes. In addition, we consider scalar perturbations on this background geometry and compute the corresponding quasinormal modes. Moreover, we discuss the late-time behavior of the perturbations finding an interesting new feature, i.e., the presence of a subdominant power-law tail term. Likewise, we compute the Bekenstein entropy bound and the first semiclassical correction to the black hole entropy using the brick wall method, showing their universality. Finally, we also discuss the thermodynamical stability of the model.

scholarly journals Imprints of r-process heating on fall-back accretion: distinguishing black hole–neutron star from double neutron star mergers

2019 ◽  
Vol 485 (3) ◽  
pp. 4404-4412 ◽  
Author(s):  
D Desai ◽  
B D Metzger ◽  
F Foucart
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Gamma Ray ◽  
Late Time ◽  
X Ray ◽  
Power Law Decay ◽  
Process Heating ◽  
R Process ◽  
The Impact

ABSTRACT Mergers of compact binaries containing two neutron stars (NS–NS), or a neutron star and a stellar mass black hole (NS–BH), are likely progenitors of short-duration gamma-ray bursts (SGRBs). A fraction ${\gtrsim } 20{{\ \rm per\ cent}}$ of SGRBs is followed by temporally extended (≳minute-long), variable X-ray emission, attributed to ongoing activity of the central engine. One source of late-time engine activity is fall-back accretion of bound tidal ejecta; however, observed extended emission light curves do not track the naively anticipated, uninterrupted t−5/3 power-law decay, instead showing a lull or gap in emission typically lasting tens of seconds after the burst. Here, we re-examine the impact of heating due to rapid neutron capture (r-process) nucleosynthesis on the rate of the fall-back accretion, using ejecta properties extracted from numerical relativity simulations of NS–BH mergers. Heating by the r-process has its greatest impact on marginally bound matter, hence its relevance to late-time fall-back. Depending on the electron fraction of the ejecta and the mass of the remnant black hole, r-process heating can imprint a range of fall-back behaviour, ranging from temporal gaps of up to tens of seconds to complete late-time cut-off in the accretion rate. This behaviour is robust to realistic variations in the nuclear heating experienced by different parts of the ejecta. Central black holes with masses ${\lesssim } 3\, \mathrm{M}_{\odot }$ typically experience absolute cut-offs in the fall-back rate, while more massive ${\gtrsim } 6\!-\!8\, \mathrm{M}_{\odot }$ black holes instead show temporal gaps. We thus propose that SGRBs showing extended X-ray emission arise from NS–BH, rather than NS–NS, mergers. Our model implies an NS–BH merger detection rate by LIGO that, in steady state, is comparable to or greater than that of NS–NS mergers.

scholarly journals HIDDEN SUPERSYMMETRY IN DIRAC FERMION QUASINORMAL MODES OF BLACK HOLES

2013 ◽  
Vol 28 (15) ◽  
pp. 1350057 ◽  
Author(s):  
V. K. OIKONOMOU
Keyword(s):  
Black Holes ◽  
Quasinormal Modes ◽  
Dirac Fermion ◽  
Dirac Fermions ◽  
Radial Part ◽  
Massless Fermion ◽  
Bijective Correspondence ◽  
Curved Space ◽  
Fermionic System ◽  
Zero Modes

We connect the quasinormal modes corresponding to Dirac fermions in various curved space–time backgrounds to an N = 2 supersymmetric quantum mechanics algebra, which can be constructed from the radial part of the fermionic solutions of the Dirac equation. In the massless fermion case, the quasinormal modes are in bijective correspondence with the zero modes of the fermionic system and this results to unbroken supersymmetry. The massive case is more complicated, but as we demonstrate, supersymmetry remains unbroken even in this case.

scholarly journals A New Approach to Black Hole Quasinormal Modes: A Review of the Asymptotic Iteration Method

2012 ◽  
Vol 2012 ◽  
pp. 1-42 ◽  
Author(s):  
H. T. Cho ◽  
A. S. Cornell ◽  
Jason Doukas ◽  
T.-R. Huang ◽  
Wade Naylor
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Iteration Method ◽  
Quasinormal Modes ◽  
Kerr Black Hole ◽  
Asymptotic Iteration Method ◽  
Wkb Method ◽  
New Approach ◽  
Higher Dimensional ◽  
First Time

We discuss how to obtain black hole quasinormal modes (QNMs) using the asymptotic iteration method (AIM), initially developed to solve second-order ordinary differential equations. We introduce the standard version of this method and present an improvement more suitable for numerical implementation. We demonstrate that the AIM can be used to find radial QNMs for Schwarzschild, Reissner-Nordström (RN), and Kerr black holes in a unified way. We discuss some advantages of the AIM over the continued fractions method (CFM). This paper presents for the first time the spin 0, 1/2 and 2 QNMs of a Kerr black hole and the gravitational and electromagnetic QNMs of the RN black hole calculated via the AIM and confirms results previously obtained using the CFM. We also present some new results comparing the AIM to the WKB method. Finally we emphasize that the AIM is well suited to higher-dimensional generalizations and we give an example of doubly rotating black holes.

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