643 research outputs found
Quasinormal modes and stability of the rotating acoustic black hole: numerical analysis
The study of the quasinormal modes (QNMs) of the 2+1 dimensional rotating
draining bathtub acoustic black hole, the closest analogue found so far to the
Kerr black hole, is performed. Both the real and imaginary parts of the
quasinormal (QN) frequencies as a function of the rotation parameter B are
found through a full non-linear numerical analysis. Since there is no change in
sign in the imaginary part of the frequency as B is increased we conclude that
the 2+1 dimensional rotating draining bathtub acoustic black hole is stable
against small perturbations.Comment: 6 pages, ReVTeX4. v2. References adde
Detection of Gravitational Waves from the Coalescence of Population-III Remnants with Advanced LIGO
The comoving mass density of massive black hole (MBH) remnants from
pre-galactic star formation could have been similar in magnitude to the
mass-density of supermassive black holes (SMBHs) in the present-day universe.
We show that the fraction of MBHs that coalesce during the assembly of SMBHs
can be extracted from the rate of ring-down gravitational waves that are
detectable by Advanced LIGO. Based on the SMBH formation history inferred from
the evolution of the quasar luminosity function, we show that an observed event
rate of 1 per year will constrain the SMBH mass fraction that was contributed
by MBHs coalescence down to a level of ~10^-6 for 20 solar mass MBH remnants
(or ~10^-4 for 260 solar mass remnants).Comment: 4 pages, 2 figures. Submitted to ApJ Letter
Asymptotic Quasinormal Frequencies of Different Spin Fields in Spherically Symmetric Black Holes
We consider the asymptotic quasinormal frequencies of various spin fields in
Schwarzschild and Reissner-Nordstr\"om black holes. In the Schwarzschild case,
the real part of the asymptotic frequency is ln3 for the spin 0 and the spin 2
fields, while for the spin 1/2, the spin 1, and the spin 3/2 fields it is zero.
For the non-extreme charged black holes, the spin 3/2 Rarita-Schwinger field
has the same asymptotic frequency as that of the integral spin fields. However,
the asymptotic frequency of the Dirac field is different, and its real part is
zero. For the extremal case, which is relevant to the supersymmetric
consideration, all the spin fields have the same asymptotic frequency, the real
part of which is zero. For the imaginary parts of the asymptotic frequencies,
it is interesting to see that it has a universal spacing of for all the
spin fields in the single-horizon cases of the Schwarzschild and the extreme
Reissner-Nordstr\"om black holes. The implications of these results to the
universality of the asymptotic quasinormal frequencies are discussed.Comment: Revtex, 17 pages, 3 eps figures; one table, some remarks and
references added to section I
Dirac Quasinormal modes of Schwarzschild black hole
The quasinormal modes (QNMs) associated with the decay of Dirac field
perturbation around a Schwarzschild black hole is investigated by using
continued fraction and Hill-determinant approaches. It is shown that the
fundamental quasinormal frequencies become evenly spaced for large angular
quantum number and the spacing is given by . The angular quantum number has the
surprising effect of increasing real part of the quasinormal frequencies, but
it almost does not affect imaginary part, especially for low overtones. In
addition, the quasinormal frequencies also become evenly spaced for large
overtone number and the spacing for imaginary part is
which is same as that of the
scalar, electromagnetic, and gravitational perturbations.Comment: 14 pages, 5 figure
Late-Time Tails in Gravitational Collapse of a Self-Interacting (Massive) Scalar-Field and Decay of a Self-Interacting Scalar Hair
We study analytically the initial value problem for a self-interacting
(massive) scalar-field on a Reissner-Nordstr\"om spacetime. Following the
no-hair theorem we examine the dynamical physical mechanism by which the
self-interacting (SI) hair decays. We show that the intermediate asymptotic
behaviour of SI perturbations is dominated by an oscillatory inverse power-law
decaying tail. We show that at late-times the decay of a SI hair is slower than
any power-law. We confirm our analytical results by numerical simulations.Comment: 16 pages, 3 ps figures, Revte
The scalar perturbation of the higher-dimensional rotating black holes
The massless scalar field in the higher-dimensional Kerr black hole (Myers-
Perry solution with a single rotation axis) has been investigated. It has been
shown that the field equation is separable in arbitrary dimensions. The
quasi-normal modes of the scalar field have been searched in five dimensions
using the continued fraction method. The numerical result shows the evidence
for the stability of the scalar perturbation of the five-dimensional Kerr black
holes. The time scale of the resonant oscillation in the rapidly rotating black
hole, in which case the horizon radius becomes small, is characterized by
(black hole mass)^{1/2}(Planck mass)^{-3/2} rather than the light-crossing time
of the horizon.Comment: 16 pages, 7 figures, revised versio
Close-limit analysis for head-on collision of two black holes in higher dimensions: Brill-Lindquist initial data
Motivated by the TeV-scale gravity scenarios, we study gravitational
radiation in the head-on collision of two black holes in higher dimensional
spacetimes using a close-limit approximation. We prepare time-symmetric initial
data sets for two black holes (the so-called Brill-Lindquist initial data) and
numerically evolve the spacetime in terms of a gauge invariant formulation for
the perturbation around the higher-dimensional Schwarzschild black holes. The
waveform and radiated energy of gravitational waves emitted in the head-on
collision are clarified. Also, the complex frequencies of fundamental
quasinormal modes of higher-dimensional Schwarzschild black holes, which have
not been accurately derived so far, are determined.Comment: 27 pages, 8 figures, published versio
Quasinormal Ringing for Acoustic Black Holes at Low Temperature
We investigate a condensed matter ``black hole'' analogue, taking the
Gross-Pitaevskii (GP) equation as a starting point. The linearized GP equation
corresponds to a wave equation on a black hole background, giving quasinormal
modes under some appropriate conditions. We suggest that we can know the
detailed characters and corresponding geometrical information about the
acoustic black hole by observing quasinormal ringdown waves in the low
temperature condensed matters.Comment: 9 pages, 3 figures, PRD accepted versio
Massive scalar field quasi-normal modes of higher dimensional black holes
We study quasinormal spectrum of massive scalar field in the -dimensional
black hole background. We found the qualitatively different dependence on the
field mass of the fundamental modes for . The behaviour of higher modes
is qualitatively the same for all . Thus for some particular values of mass
(of the field and of the black hole) the spectrum has two dominating
oscillations with a very long lifetime. Also we show that the asymptotically
high overtones do not depend on the field mass. In addition, we present the
generalisation of the Nollert improvement of the continued fraction technique
for the numerical calculation of quasi-normal frequencies of -dimensional
black holes.Comment: 8 pages, 4 figures, misprints corrected, version to appear in Phys.
Rev.
Binary black hole merger dynamics and waveforms
We study dynamics and radiation generation in the last few orbits and merger
of a binary black hole system, applying recently developed techniques for
simulations of moving black holes. Our analysis of the gravitational radiation
waveforms and dynamical black hole trajectories produces a consistent picture
for a set of simulations with black holes beginning on circular-orbit
trajectories at a variety of initial separations. We find profound agreement at
the level of one percent among the simulations for the last orbit, merger and
ringdown. We are confident that this part of our waveform result accurately
represents the predictions from Einstein's General Relativity for the final
burst of gravitational radiation resulting from the merger of an astrophysical
system of equal-mass non-spinning black holes. The simulations result in a
final black hole with spin parameter a/m=0.69. We also find good agreement at a
level of roughly 10 percent for the radiation generated in the preceding few
orbits.Comment: 11 pages, 11 figures, submitted to PRD, update citations, minor
change
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