Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasinormal modes of Gauss-Bonnet-AdS black holes: towards holographic
  description of finite coupling   Here we shall show that there is no other instability for the
Einstein-Gauss-Bonnet-anti-de Sitter (AdS) black holes, than the eikonal one
and consider the features of the quasinormal spectrum in the stability sector
in detail. The obtained quasinormal spectrum consists from the two essentially
different types of modes: perturbative and non-perturbative in the Gauss-Bonnet
coupling $\alpha$. The sound and hydrodynamic modes of the perturbative branch
can be expressed through their Schwazrschild-AdS limits by adding a linear in
$\alpha$ correction to the damping rates: $\omega \approx Re(\omega_{SAdS}) -
Im(\omega_{SAdS}) (1 - \alpha \cdot ((D+1) (D-4) /2 R^2)) i$, where $R$ is the
AdS radius. The non-perturbative branch of modes consists of purely imaginary
modes, whose damping rates unboundedly increase when $\alpha$ goes to zero.
When the black hole radius is much larger than the anti-de Sitter radius $R$,
the regime of the black hole with planar horizon (black brane) is reproduced.
If the Gauss-Bonnet coupling $\alpha$ (or used in holography $\lambda_{GB}$) is
not small enough, then the black holes and branes suffer from the instability,
so that the holographic interpretation of perturbation of such black holes
becomes questionable, as, for example, the claimed viscosity bound violation in
the higher derivative gravity. For example, $D=5$ black brane is unstable at
$|\lambda_{GB}|>1/8$ and has anomalously large relaxation time when approaching
the threshold of instability.

13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: econ