135 research outputs found
Analytic calculation of quasi-normal modes
We discuss the analytic calculation of quasi-normal modes of various types of
perturbations of black holes both in asymptotically flat and anti-de Sitter
spaces. We obtain asymptotic expressions and also show how corrections can be
calculated perturbatively. We pay special attention to low-frequency modes in
anti-de Sitter space because they govern the hydrodynamic properties of a gauge
theory fluid according to the AdS/CFT correspondence. The latter may have
experimental consequencies for the quark-gluon plasma formed in heavy ion
collisions.Comment: 33 pages, prepared for the proceedings of the 4th Aegean Summer
School on Black Holes, Mytilene, Greece, September 200
Perturbative calculation of quasi-normal modes of AdS Schwarzschild black holes
We calculate analytically quasi-normal modes of AdS Schwarzschild black holes
including first-order corrections. We consider massive scalar, gravitational
and electromagnetic perturbations. Our results are in good agreement with
numerical calculations. In the case of electromagnetic perturbations, ours is
the first calculation to provide an analytic expression for quasi-normal
frequencies, because the effective potential vanishes at zeroth order. We show
that the first-order correction is logarithmic.Comment: 20 pages incl. 8 figures (using eepic and color
Asymptotic form of quasi-normal modes of large AdS black holes
We discuss a method of calculating analytically the asymptotic form of
quasi-normal frequencies for large AdS black holes in five dimensions. In this
case, the wave equation reduces to a Heun equation. We show that the Heun
equation may be approximated by a Hypergeometric equation at large frequencies.
Thus we obtain the asymptotic form of quasi-normal frequencies in agreement
with numerical results. We also present a simple monodromy argument that leads
to the same results. We include a comparison with the three-dimensional case in
which exact expressions are derived.Comment: 10 page
On quasi-normal modes and the AdS_5/CFT_4 correspondence
We discuss the quasi-normal modes of massive scalar perturbations of black
holes in AdS_5 in conjunction with the AdS/CFT correspondence. On the gravity
side, we solve the wave equation and obtain an expression for the asymptotic
form of quasi-normal frequencies. We then show that these expressions agree
with those obtained from a CFT defined on in a certain
scaling limit, by identifying Euclidean time with one of the periodic
coordinates. This generalizes known exact results in three dimensions (BTZ
black hole). As a by-product, we derive the standard energy quantization
condition in AdS by a simple monodromy argument in complexified AdS space. This
argument relies on an unphysical singularity.Comment: v2: 20 pages, added discussion on geometric origin of results,
corrected typos; to appear in Nucl. Phys.
Perturbations of anti-de Sitter black holes
I review perturbations of black holes in asymptotically anti-de Sitter space.
I show how the quasi-normal modes governing these perturbations can be
calculated analytically and discuss the implications on the hydrodynamics of
gauge theory fluids per the AdS/CFT correspondence. I also discuss phase
transitions of hairy black holes with hyperbolic horizons and the dual
superconductors emphasizing the analytical calculation of their properties.Comment: 25 pages, 4 figures, prepared for the proceedings of the 5th Aegean
Summer School "From Gravity to Thermal Gauge Theories: the AdS/CFT
Correspondence," Milos, Greece, September 2009
Geometric Finiteness and Non-quasinormal Modes of the BTZ Black Hole
The BTZ black hole is geometrically finite. This means that its three
dimensional hyperbolic structure as encoded in its metric is in 1-1
correspondence with the Teichmuller space of its boundary, which is a two
torus. The equivalence of different Teichmuller parameters related by the
action of the modular group therefore requires the invariance of the
monodromies of the solutions of the wave equation around the inner and outer
horizons in the BTZ background. We show that this invariance condition leads to
the non-quasinormal mode frequencies discussed by Birmingham and Carlip.Comment: 8 Pages, Latex file, minor changes in the text, journal versio
Low frequency quasi-normal modes of AdS black holes
We calculate analytically low frequency quasi-normal modes of gravitational
perturbations of AdS Schwarzschild black holes in dimensions. We arrive at
analytic expressions which are in agreement with their counterparts from
linearized hydrodynamics in , in accordance with the
AdS/CFT correspondence. Our results are also in good agreement with results of
numerical calculations.Comment: 14 page
Perturbative calculation of quasi-normal modes of arbitrary spin in Schwarzschild spacetime
We calculate analytically the asymptotic form of quasi-normal modes of
perturbations of arbitrary spin of a Schwarzschild black hole including
first-order corrections. We use the Teukolsky equation which applies to both
bosonic and fermionic modes. Remarkably, we arrive at explicit expressions
which coincide with those derived using the Regge-Wheeler equation for integer
spin. Our zeroth-order expressions agree with the results of WKB analysis. In
the case of Dirac fermions, our results are in good agreement with numerical
data.Comment: 13 pages incl. 3 figures, v2: corrected error, generalized results to
arbitrary spi
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