3,515 research outputs found

### A note on the quantization of a multi-horizon black hole

We consider the quasinormal spectrum of a charged scalar field in the
(charged) Reissner-Nordstrom spacetime, which has two horizons. The spectrum is
characterized by two distinct families of asymptotic resonances. We suggest and
demonstrate the according to Bohr's correspondence principle and in agreement
with the Bekenstein-Mukhanov quantization scheme, one of these resonances
corresponds to a fundamental change of Delta A=4hbar ln2 in the surface area of
the black-hole outer horizon. The second asymptotic resonance is associated
with a fundamental change of Delta Atot=4hbar ln3 in the total area of the
black hole (in the sum of the surface areas of the inner and outer horizons),
in accordance with a suggestion of Makela and Repo.Comment: 6 page

### Late-Time Evolution of Charged Gravitational Collapse and Decay of Charged Scalar Hair - II

We study analytically the initial value problem for a charged massless
scalar-field on a Reissner-Nordstr\"om spacetime. Using the technique of
spectral decomposition we extend recent results on this problem. Following the
no-hair theorem we reveal the dynamical physical mechanism by which the charged
hair is radiated away. We show that the charged perturbations decay according
to an inverse power-law behaviour at future timelike infinity and along future
null infinity. Along the future outer horizon we find an oscillatory inverse
power-law relaxation of the charged fields. We find that a charged black hole
becomes ``bald'' slower than a neutral one, due to the existence of charged
perturbations. Our results are also important to the study of mass-inflation
and the stability of Cauchy horizons during a dynamical gravitational collapse
of charged matter in which a charged black-hole is formed.Comment: Latex 15 pages, Revtex.st

### Mode-coupling in rotating gravitational collapse: Gravitational and electromagnetic perturbations

We consider the late-time evolution of {\it gravitational} and
electromagnetic perturbations in realistic {\it rotating} Kerr spacetimes. We
give a detailed analysis of the mode-coupling phenomena in rotating
gravitational collapse. A consequence of this phenomena is that the late-time
tail is dominated by modes which, in general, may have an angular distribution
different from the original one. In addition, we show that different types of
fields have {\it different} decaying rates. This result turns over the
traditional belief (which has been widely accepted during the last three
decades) that the late-time tail of gravitational collapse is universal.Comment: 16 page

### Radiative falloff of a scalar field in a weakly curved spacetime without symmetries

We consider a massless scalar field propagating in a weakly curved spacetime
whose metric is a solution to the linearized Einstein field equations. The
spacetime is assumed to be stationary and asymptotically flat, but no other
symmetries are imposed -- the spacetime can rotate and deviate strongly from
spherical symmetry. We prove that the late-time behavior of the scalar field is
identical to what it would be in a spherically-symmetric spacetime: it decays
in time according to an inverse power-law, with a power determined by the
angular profile of the initial wave packet (Price falloff theorem). The field's
late-time dynamics is insensitive to the nonspherical aspects of the metric,
and it is governed entirely by the spacetime's total gravitational mass; other
multipole moments, and in particular the spacetime's total angular momentum, do
not enter in the description of the field's late-time behavior. This extended
formulation of Price's falloff theorem appears to be at odds with previous
studies of radiative decay in the spacetime of a Kerr black hole. We show,
however, that the contradiction is only apparent, and that it is largely an
artifact of the Boyer-Lindquist coordinates adopted in these studies.Comment: 17 pages, RevTeX

### Late-time evolution of a self-interacting scalar field in the spacetime of dilaton black hole

We investigate the late-time tails of self-interacting (massive) scalar
fields in the spacetime of dilaton black hole. Following the no hair theorem we
examine the mechanism by which self-interacting scalar hair decay. We revealed
that the intermediate asymptotic behavior of the considered field perturbations
is dominated by an oscillatory inverse power-law decaying tail. The numerical
simulations showed that at the very late-time massive self-interacting scalar
hair decayed slower than any power law.Comment: 8 pages, 4 figures, to appear in Phys. Rev.

### High-Order Contamination in the Tail of Gravitational Collapse

It is well known that the late-time behaviour of gravitational collapse is
{\it dominated} by an inverse power-law decaying tail. We calculate {\it
higher-order corrections} to this power-law behaviour in a spherically
symmetric gravitational collapse. The dominant ``contamination'' is shown to
die off at late times as $M^2t^{-4}\ln(t/M)$. This decay rate is much {\it
slower} than has been considered so far. It implies, for instance, that an
`exact' (numerical) determination of the power index to within $\sim 1 %$
requires extremely long integration times of order $10^4 M$. We show that the
leading order fingerprint of the black-hole electric {\it charge} is of order
$Q^2t^{-4}$.Comment: 12 pages, 2 figure

### Radiative falloff in the background of rotating black hole

We study numerically the late-time tails of linearized fields with any spin
$s$ in the background of a spinning black hole. Our code is based on the
ingoing Kerr coordinates, which allow us to penetrate through the event
horizon. The late time tails are dominated by the mode with the least multipole
moment $\ell$ which is consistent with the equatorial symmetry of the initial
data and is equal to or greater than the least radiative mode with $s$ and the
azimuthal number $m$.Comment: 5 pages, 4 Encapsulated PostScript figures; Accepted to Phys. Rev. D
(Rapid Communication

### Late-time evolution of the Yang-Mills field in the spherically symmetric gravitational collapse

We investigate the late-time evolution of the Yang-Mills field in the
self-gravitating backgrounds: Schwarzschild and Reissner-Nordstr\"om
spacetimes. The late-time power-law tails develop in the three asymptotic
regions: the future timelike infinity, the future null infinity and the black
hole horizon. In these two backgrounds, however, the late-time evolution has
quantitative and qualitative differences. In the Schwarzschild black hole
background, the late-time tails of the Yang-Mills field are the same as those
of the neutral massless scalar field with multipole moment l=1. The late-time
evolution is dominated by the spacetime curvature. When the background is the
Reissner-Nordstr\"om black hole, the late-time tails have not only a smaller
power-law exponent, but also an oscillatory factor. The late-time evolution is
dominated by the self-interacting term of the Yang-Mills field. The cause
responsible for the differences is revealed.Comment: Revtex, 14 pages, no figure

### Numerical simulation of the massive scalar field evolution in the Reissner-Nordstr\"{o}m black hole background

We studied the massive scalar wave propagation in the background of
Reissner-Nordstr\"{o}m black hole by using numerical simulations. We learned
that the value $Mm$ plays an important role in determining the properties of
the relaxation of the perturbation. For $Mm << 1$ the relaxation process
depends only on the field parameter and does not depend on the spacetime
parameters. For $Mm >> 1$, the dependence of the relaxation on the black hole
parameters appears. The bigger mass of the black hole, the faster the
perturbation decays. The difference of the relaxation process caused by the
black hole charge $Q$ has also been exhibited.Comment: Accepted for publication in Phys. Rev.

### Late-Time Evolution of Realistic Rotating Collapse and The No-Hair Theorem

We study analytically the asymptotic late-time evolution of realistic
rotating collapse. This is done by considering the asymptotic late-time
solutions of Teukolsky's master equation, which governs the evolution of
gravitational, electromagnetic, neutrino and scalar perturbations fields on
Kerr spacetimes. In accordance with the no-hair conjecture for rotating
black-holes we show that the asymptotic solutions develop inverse power-law
tails at the asymptotic regions of timelike infinity, null infinity and along
the black-hole outer horizon (where the power-law behaviour is multiplied by an
oscillatory term caused by the dragging of reference frames). The damping
exponents characterizing the asymptotic solutions at timelike infinity and
along the black-hole outer horizon are independent of the spin parameter of the
fields. However, the damping exponents at future null infinity are spin
dependent. The late-time tails at all the three asymptotic regions are
spatially dependent on the spin parameter of the field. The rotational dragging
of reference frames, caused by the rotation of the black-hole (or star) leads
to an active coupling of different multipoles.Comment: 16 page

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