2,430 research outputs found
Large Deviations Principle for a Large Class of One-Dimensional Markov Processes
We study the large deviations principle for one dimensional, continuous,
homogeneous, strong Markov processes that do not necessarily behave locally as
a Wiener process. Any strong Markov process in that is
continuous with probability one, under some minimal regularity conditions, is
governed by a generalized elliptic operator , where and are
two strictly increasing functions, is right continuous and is
continuous. In this paper, we study large deviations principle for Markov
processes whose infinitesimal generator is where
. This result generalizes the classical large deviations
results for a large class of one dimensional "classical" stochastic processes.
Moreover, we consider reaction-diffusion equations governed by a generalized
operator . We apply our results to the problem of wave front
propagation for these type of reaction-diffusion equations.Comment: 23 page
Horava Gravity and Gravitons at a Conformal Point
Recently Horava proposed a renormalizable gravity theory with higher
derivatives by abandoning the Lorenz invariance in UV. Here, I study the Horava
model at , where an anisotropic Weyl symmetry exists in the UV
limit, in addition to the foliation-preserving diffeomorphism. By considering
linear perturbations around Minkowski vacuum, I show that the scalar graviton
mode is completely disappeared and only the usual tensor graviton modes remain
in the physical spectrum. The existence of the UV conformal symmetry is unique
to the theory with the detailed balance and it is quite probable that
be the UV fixed point. This situation is analogous to
, which is Lorentz invariant in the IR limit and is believed to be
the IR fixed point.Comment: Added comments and references, Accepted in GER
Absorption cross section in the topologically massive gravity at the critical point
The absorption cross section for the the warped AdS black hole background
shows that it is larger than the area even if the s-wave limit is considered.
It raises some question whether the deviation from the areal cross section is
due to the warped configuration of the geometry or the rotating coordinate
system, where these two effects are mixed up in the warped AdS black hole.
So, we study the low-frequency scattering dynamics of propagating scalar fields
under the warped AdS background at the critical point which reduces to the
BTZ black hole in the rotating frame without the warped factor, which shows
that the deformation effect at the critical point does not appear.Comment: 12 pages, LaTe
Quasi-multi-Regge Processes with a Quark Exchange in the t-channel
The QCD amplitudes for particle's production in the quasi-multi-Regge
kinematics with a quark exchange in crossing channels are calculated in the
Born approximation. In particular they are needed to find next-to-leading
corrections to the quark Regge trajectory and to the integral kernel of the
Bethe-Salpeter equation for the t-channel partial wave with fermion quantum
numbers and a negative signature. The gauge-invariant action for the
interaction of the reggeized quarks and gluons with the usual particles is
constructed.Comment: LaTeX, 10 page
Electromagnetic properties of graphene junctions
A resonant chiral tunneling (CT) across a graphene junction (GJ) induced by
an external electromagnetic field (EF) is studied. Modulation of the electron
and hole wavefunction phases by the external EF during the CT
processes strongly impacts the CT directional diagram. Therefore the a.c.
transport characteristics of GJs depend on the EF polarization and frequency
considerably. The GJ shows great promises for various nanoelectronic
applications working in the THz diapason.Comment: 4 pages 3 figure
Autonomous stochastic resonance in fully frustrated Josephson-junction ladders
We investigate autonomous stochastic resonance in fully frustrated
Josephson-junction ladders, which are driven by uniform constant currents. At
zero temperature large currents induce oscillations between the two ground
states, while for small currents the lattice potential forces the system to
remain in one of the two states. At finite temperatures, on the other hand,
oscillations between the two states develop even below the critical current;
the signal-to-noise ratio is found to display array-enhanced stochastic
resonance. It is suggested that such behavior may be observed experimentally
through the measurement of the staggered voltage.Comment: 6 pages, 11 figures, to be published in Phys. Rev.
On the Calculation of the NLO Virtual Photon Impact Factor
The definition of the virtual photon impact factor involves the integration
of the s-channel discontinuity of the photon-Reggeon scattering amplitude over
the right cut. It permits to formulate a new approach for the calculation of
the impact factor based on analytical properties of the amplitude in question.
In the next-to-leading order it may give a possibility for considerable
simplification of the calculation. We have shown that a part of the diagrams
contributing to the impact factor can be treated without their real
calculation.Comment: 18 pages, latex, axodraw.sty for figures, version to appear in Nucl.
Phys.
Capacitance of MnO2 Micro-Flowers Decorated CNFs in Alkaline Electrolyte and Its Bi-Functional Electrocatalytic Activity toward Hydrazine Oxidation
Well-dispersed MnO2 micro-flowers were grown directly on carbon nanofibers via a simple hydrothermal technique without any template. Structure and morphology were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) equipped with rapid energy dispersive analysis X-ray (EDX). The appealed characterization techniques specified that the obtained material is carbon nanofibers decorated by MnO2 micro-flowers. Super capacitive performance of the MnO2 micro-flowers decorated CNFs as active electrode material was evaluated by cyclic voltammetry (CV) in alkaline medium and yield a reasonable specific capacitance of 120 Fg−1 at 5 mV s−1. As an electrocatalyst for hydrazine oxidation, the MnO2 micro-flowers decorated CNFs showed high current density. The impressive bi-functional electrochemical activity of MnO2 micro-flowers decorated CNFs is mainly attributed to its unique architectural structure.This Research was financially supported by National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MSIP) (No. 2014R1A4A1008140
Extremal black holes in the Ho\v{r}ava-Lifshitz gravity
We study the near-horizon geometry of extremal black holes in the
Ho\v{r}ava-Lifshitz gravity with a flow parameter . For ,
near-horizon geometry of extremal black holes are AdS with
different radii, depending on the (modified) Ho\v{r}ava-Lifshitz gravity. For
, the radius of is negative, which means
that the near-horizon geometry is ill-defined and the corresponding
Bekenstein-Hawking entropy is zero. We show explicitly that the entropy
function approach does not work for obtaining the Bekenstein-Hawking entropy of
extremal black holes.Comment: 18 pages, v2:some points on Lifshitz black holes claified, v3:
version to appear in EJP
Thermodynamics of a black hole based on a generalized uncertainty principle
We study thermodynamic quantities and the stability of a black hole in a
cavity using the Euclidean action formalism by Gibbons and Hawking based on the
generalized uncertainty relation which is extended in a symmetric way with
respect to the space and momentum without loss of generality. Two parameters in
the uncertainty relation affect the thermodynamical quantities such as energy,
entropy, and the heat capacity. In particular, it can be shown that the small
black hole is unstable and it may decay either into a minimal black hole or a
large black hole. We discuss a constraint for a large black hole comparable to
the size of the cavity in connection with the critical mass.Comment: 12 pages, 4 figures; v2. to appear in JHE
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