19,809 research outputs found
Static Gauss-Bonnet Black Holes at Large
We study the static black holes in the large dimensions in the
Gauss-Bonnet gravity with a cosmological constant, coupled to the Maxewell
theory. After integrating the equation of motion with respect to the radial
direction, we obtain the effective equations at large to describe the
nonlinear dynamical deformations of the black holes. From the perturbation
analysis on the effective equations, we get the analytic expressions of the
frequencies for the quasinormal modes of charge and scalar-type perturbations.
We show that for a positive Gauss-Bonnet term, the black hole could become
unstable only if the cosmological constant is positive, otherwise the black
hole is always stable. However, for a negative Gauss-Bonnet term, we find that
the black hole could always be unstable. The instability of the black hole
depends not only on the cosmological constant and the charge, but also
significantly on the Gauss-Bonnet term. Moreover, at the onset of instability
there is a non-trivial static zero-mode perturbation, which suggests the
existence of a new non-spherically symmetric solution branch. We construct the
non-spherical symmetric static solutions of the large effective equations
explicitly.Comment: 27 pages, 34 figures. arXiv admin note: text overlap with
arXiv:1607.0471
Inflation with Holographic Dark Energy
We investigate the corrections of the holographic dark energy to inflation
paradigm. We study the evolution of the holographic dark energy in the
inflationary universe in detail, and carry out a model-independent analysis on
the holographic dark energy correction to the primordial scalar power spectrum.
It turns out that the corrections generically make the spectrum redder. To be
consistent with the experimental data, there must be a upper bound on the
reheating temperature. We also discuss the corrections due to different choices
of the infrared cutoff.Comment: 15 pages, 3 figures, v2: references added, a fast-roll discussion
added. v3: typos corrected. v4: final version to appear in NP
Corrections to holographic entanglement plateau
We investigate the robustness of the Araki-Lieb inequality in a
two-dimensional (2D) conformal field theory (CFT) on torus. The inequality
requires that is nonnegative, where
is the thermal entropy and , are the entanglement
entropies. Holographically there is an entanglement plateau in the BTZ black
hole background, which means that there exists a critical length such that when
the inequality saturates . In thermal AdS
background, the holographic entanglement entropy leads to for
arbitrary . We compute the next-to-leading order contributions to in the large central charge CFT at both high and low temperatures. In both
cases we show that is strictly positive except for or
. This turns out to be true for any 2D CFT. In calculating the single
interval entanglement entropy in a thermal state, we develop new techniques to
simplify the computation. At a high temperature, we ignore the finite size
correction such that the problem is related to the entanglement entropy of
double intervals on a complex plane. As a result, we show that the leading
contribution from a primary module takes a universal form. At a low
temperature, we show that the leading thermal correction to the entanglement
entropy from a primary module does not take a universal form, depending on the
details of the theory.Comment: 32 pages, 8 figures; V2, typos corrected, published versio
The Fate of Massive Closed Strings
We calculate the semi-inclusive decay rate of an average string state with
toroidal compactification in the the superstring theory. We also apply this
calculation to a brane-inflation model in a warped geometry and find that the
decay rate is greatly suppressed if the final strings are both massive and
enhanced for massless radiation.Comment: 4 pages, to appear in the proceeding of PASCOS 2005, Gyeongju, Korea,
May 30-June 4, 200
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