11 research outputs found
Gravitational quasinormal modes of AdS black branes in d spacetime dimensions
The AdS/CFT duality has established a mapping between quantities in the bulk
AdS black-hole physics and observables in a boundary finite-temperature field
theory. Such a relationship appears to be valid for an arbitrary number of
spacetime dimensions, extrapolating the original formulations of Maldacena's
correspondence. In the same sense properties like the hydrodynamic behavior of
AdS black-hole fluctuations have been proved to be universal. We investigate in
this work the complete quasinormal spectra of gravitational perturbations of
-dimensional plane-symmetric AdS black holes (black branes). Holographically
the frequencies of the quasinormal modes correspond to the poles of two-point
correlation functions of the field-theory stress-energy tensor. The important
issue of the correct boundary condition to be imposed on the gauge-invariant
perturbation fields at the AdS boundary is studied and elucidated in a fully
-dimensional context. We obtain the dispersion relations of the first few
modes in the low-, intermediate- and high-wavenumber regimes. The sound-wave
(shear-mode) behavior of scalar (vector)-type low-frequency quasinormal mode is
analytically and numerically confirmed. These results are found employing both
a power series method and a direct numerical integration scheme.Comment: added references, typos corrected, minor changes, final version for
JHE
Perturbative Calculation of Quasinormal Modes of --Dimensional Black Holes
We study analytically quasinormal modes in a wide variety of black hole
spacetimes, including --dimensional asymptotically flat spacetimes and
non-asymptotically flat spacetimes (particular attention has been paid to the
four dimensional case). We extend the analytical calculation to include
first-order corrections to analytical expressions for quasinormal mode
frequencies by making use of a monodromy technique. All possible type
perturbations are included in this paper. The calculation performed in this
paper show that systematic expansions for uncharged black holes include
different corrections with the ones for charged black holes. This difference
makes them have a different --dependence relation in the first-order
correction formulae. The method applied above in calculating the first-order
corrections of quasinormal mode frequencies seems to be unavailable for black
holes with small charge. This result supports the Neitzke's prediction. On what
concerns quantum gravity we confirm the view that the in
Schwarzschild seems to be nothing but some numerical coincidences.Comment: 49 pages, 5 figure
Quasinormal modes and hidden conformal symmetry in the Reissner-Nordstrom black hole
It is shown that the scalar wave equation in the near-horizon limit respects
a hidden SL(2,R) invariance in the Reissner-Nordstrom (RN) black hole
spacetimes. We use the SL(2,R) symmetry to determine algebraically the purely
imaginary quasinormal frequencies of the RN black hole. We confirm that these
are exactly quasinormal modes of scalar perturbation around the near-extremal
black hole.Comment: 17 pages, 1 figure, version to appear in EPJ
Black Hole Chromosphere at the LHC
If the scale of quantum gravity is near a TeV, black holes will be copiously
produced at the LHC. In this work we study the main properties of the light
descendants of these black holes. We show that the emitted partons are closely
spaced outside the horizon, and hence they do not fragment into hadrons in
vacuum but more likely into a kind of quark-gluon plasma. Consequently, the
thermal emission occurs far from the horizon, at a temperature characteristic
of the QCD scale. We analyze the energy spectrum of the particles emerging from
the "chromosphere", and find that the hard hadronic jets are almost entirely
suppressed. They are replaced by an isotropic distribution of soft photons and
hadrons, with hundreds of particles in the GeV range. This provides a new
distinctive signature for black hole events at LHC.Comment: Incorporates changes made for the version to be published in Phys.
Rev. D. Additional details provided on the effect of the chromosphere in
cosmic ray shower
Black Hole Thermodynamics and Statistical Mechanics
We have known for more than thirty years that black holes behave as
thermodynamic systems, radiating as black bodies with characteristic
temperatures and entropies. This behavior is not only interesting in its own
right; it could also, through a statistical mechanical description, cast light
on some of the deep problems of quantizing gravity. In these lectures, I review
what we currently know about black hole thermodynamics and statistical
mechanics, suggest a rather speculative "universal" characterization of the
underlying states, and describe some key open questions.Comment: 35 pages, Springer macros; for the Proceedings of the 4th Aegean
Summer School on Black Hole
Periodicity and area spectrum of black holes
The recent speculation of Maggiore that the periodicity of a black hole may
be the origin of the area quantization law is confirmed. We exclusively utilize
the period of motion of an outgoing wave, which is shown to be related to the
vibrational frequency of the perturbed black hole, to quantize the horizon
areas of a Schwarzschild black hole and a Kerr black hole. It is shown that the
equally spaced area spectrum for both cases takes the same form and the spacing
is the same as that obtained through the quasinormal mode frequencies.
Particularly, for a Kerr black hole, the small angular momentum assumption,
which is necessary from the perspective of quasinormal mode, is not employed as
the general area spacing is reproduced.Comment: 5 pages, 0 figures, minor modifications to the text (results
unchanged