2,250 research outputs found
Entropic force and entanglement system
We introduce the isothermal cavity, static holographic screen, and
accelerating surface as holographic screen to study the entropic force in the
presence of the Schwarzschild black hole. These may merge to provide a
consistent holographic screen to define the entropic force on the stretched
horizon near the event horizon. Considering the similarity between the
stretched horizon of black hole and the entanglement system, we may define the
entropic force in the entanglement system without referring the source mass.Comment: 17 pages, 2 figures, version to appear in PR
Noncommutative spacetime effect on the slow-roll period of inflation
We study how the noncommutative spacetime affects on inflation. First we
obtain the noncommutative power spectrum of the curvature perturbations
produced during inflation in the slow-roll approximation. This is the explicit
-dependent power spectrum up to first order in slow-roll parameters
including the noncommutative parameter . In order to
test the role of further, we calculate the noncommutative power spectrum
using the slow-roll expansion. We find corrections which arise from the change
of pivot scale and a noncommutative parameter with constant. It
turns out that the noncommutative parameter could be considered as a
zeroth order slow-roll parameter and the noncommutative spacetime effect
suppresses the power spectrum.Comment: 13 page
Nonexistence of quasinormal modes in the extremal BTZ black hole
We show that quasinormal modes cannot exist in the extremal BTZ black hole.
For this purpose, we consider propagations of a minimally coupled scalar and a
single massive graviton obtained from the cosmological topologically massive
gravity on the extremal BTZ black hole. The would-be quasinormal modes for a
scalar and graviton could not exist because it is impossible to make an ingoing
flux into the extremal (degenerate) horizon. This is consistent with the
argument that there is no propagating dynamics in the self-dual orbifold of
AdS(3) which is just the near-horizon limit of the extremal BTZ black hole.Comment: 13 pages, 2 figures, references adde
Entropy function approach to charged BTZ black hole
We find solution to the metric function f(r)=0 of charged BTZ black hole
making use of the Lambert function. The condition of extremal charged BTZ black
hole is determined by a non-linear relation of M_e(Q)=Q^2(1-\ln Q^2). Then, we
study the entropy of extremal charged BTZ black hole using the entropy function
approach. It is shown that this formalism works with a proper normalization of
charge Q for charged BTZ black hole because AdS_2 x S^1 represents near-horizon
geometry of the extremal charged BTZ black hole. Finally, we introduce the
Wald's Noether formalism to reproduce the entropy of the extremal charged BTZ
black hole without normalization when using the dilaton gravity approach.Comment: 18 pages, 8 figures, version to appear in GR
BRST quantization of a sixth-order derivative scalar field theory
We study a sixth order derivative scalar field model in Minkowski spacetime
as a toy model of higher-derivative critical gravity theories. This model is
consistently quantized when using the Becchi-Rouet-Stora-Tyutin (BRST)
quantization scheme even though it does not show gauge symmetry manifestly.
Imposing a BRST quartet generated by two scalars and ghosts, there remains a
non-trivial subspace with positive norm. This might be interpreted as a
Minkowskian dual version of the unitary truncation in the logarithmic conformal
field theory.Comment: 13 pages, 2 figures, version to appear in MPL
Entropy of black holes in topologically massive gravity
We study the issue of black hole entropy in the topologically massive
gravity. Assuming that the presence of gravitational Chern-Simons term with the
coupling does modify the horizon radius , we propose
as the Bekenstein-Hawking entropy. This
entropy of CS-BTZ black hole satisfies the first-law of thermodynamics and the
area-law but it is slightly different from the shifted-entropy based on the BTZ black hole with outer
and inner horizon . In the case of , represents
the entropy of non-rotating BTZ black hole with the Chern-Simons term
(NBTZ-CS), while reduces to the entropy of NBTZ black hole. It shows that
may be a candidate for the entropy of the CS-BTZ black hole.Comment: 11 pages, an expanded version to discuss thermodynamic aspects of
BTZ-CS and CS-BTZ black hole
Entropic force versus temperature force
We introduce the cavity enclosing a source mass to define the temperature
force. Starting with the Tolman temperature in the stationary spacetime, we
find a non-relativistic temperature with the
Newtonian potential . This temperature could be also derived from the
Tolman-Ehrenfest effect, satisfying a relation of
with the local temperature . Finally, we derive the temperature force
which leads to the Newtonian force
law without introducing the holographic screen defined by holographic principle
and equipartition law for entropic force.Comment: 10 pages, 2 figure
Massive logarithmic graviton in the critical generalized massive gravity
We study the generalized massive gravity in three dimensional flat spacetime.
A massive logarithmic mode is propagating in the flat spacetime at the critical
point where two masses degenerate. Furthermore, we discuss the logarithmic
extension of the Galilean conformal algebra (GCA) which may arise from the
exotic and standard rank-2 logarithmic conformal field theory (LCFT) on the
boundary of AdS3 spacetime.Comment: 11 page
Recurrent delocalization and quasi-equilibration of photons in coupled circuit QED systems
We explore the photon population dynamics in two coupled circuit QED systems.
For a sufficiently weak inter-cavity photon hopping, as the photon-cavity
coupling increases, the dynamics undergoes double transitions first from a
delocalized to a localized phase and then from the localized to another
delocalized phase. The latter delocalized phase is distinguished from the
former one; instead of oscillating between the two cavities, the photons
rapidly quasi-equilibrate over the two cavities. These intrigues are attributed
to an interplay between two qualitatively distinctive nonlinear behaviors of
the circuit QED systems in the utrastrong coupling regime, whose distinction
has been widely overlooked.Comment: 5 pages; 3 figures; a typo on page 4 corrected; a change in
acknowledgment
Late-time acceleration in the coupled Cubic Galileon models
We investigate the linearly and quadratically coupled cubic Galileon models
that include linear potentials. These models may explain the late-time
acceleration. In these cases, we need two equations of state parameter named
the native and effective equations of state to test whether the universe is
accelerating or not because there is coupling between the cold dark matter and
Galileon. It turns out that there is no transition from accelerating phase to
phantom phase in the future.Comment: 14pages, 5figures, version to appear in PR
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