974 research outputs found
Quasinormal behavior of the D-dimensional Schwarzshild black hole and higher order WKB approach
We study characteristic (quasinormal) modes of a -dimensional Schwarzshild
black hole. It proves out that the real parts of the complex quasinormal modes,
representing the real oscillation frequencies, are proportional to the product
of the number of dimensions and inverse horizon radius . The
asymptotic formula for large multipole number and arbitrary is derived.
In addition the WKB formula for computing QN modes, developed to the 3rd order
beyond the eikonal approximation, is extended to the 6th order here. This gives
us an accurate and economic way to compute quasinormal frequencies.Comment: 15 pages, 6 figures, the 6th order WKB formula for computing QNMs in
Mathematica is available from https://goo.gl/nykYG
Internal quality of commercial eggs stored under conditions that simulate storage from laying to consumption
This study evaluated the effects on the internal quality of eggs of various storage environments through which eggs may pass between being laid and being consumed. Commercial eggs (N = 648) from Dekalb White hens were used. Treatments consisted of T1: 28 days at 4 °C; T2: 28 days at 20 °C; T3: 7 days at room temperature (27 °C ± 2 °C) (humidity 55%) and 21 days at 4 °C; T4: 7 days at room temperature and 21 days at 20 °C; T5: 14 days at room temperature and 14 days at 4 °C; T6: 14 days at room temperature and 14 days at 20 °C; T7: 21 days at room temperature and 7 days at 4 °C; T8: 21 days at room temperature and 7 days at 20 °C; and T9: 28 days at room temperature. The characteristics that were evaluated consisted of Haugh unit (HU), yolk index (YI), colour (L*, a* and b*), albumen pH, yolk pH and lipid oxidation. Eggs stored 28 days were darker (L*), and had greater yolk pH and lipid oxidation than fresh eggs. Eggs stored under T1 and T3 conditions had greater HU and YI than eggs stored in the other environments. The albumin pH of eggs stored at room temperature (T9) was highest of the treatments. Yellowness was increased in eggs stored under T4, T6, T8, and T9 conditions. Eggs should be stored under refrigeration as this promotes maintenance of internal quality and mitigates negative effects of previous storage conditions
SO(N) Superpotential, Seiberg-Witten Curves and Loop Equations
We consider the exact superpotential of N=1 super Yang-Mills theory with
gauge group SO(N) and arbitrary tree-level polynomial superpotential of one
adjoint Higgs field. A field-theoretic derivation of the glueball
superpotential is given, based on factorization of the N=2 Seiberg-Witten
curve. Following the conjecture of Dijkgraaf and Vafa, the result is matched
with the corresponding SO(N) matrix model prediction. The verification involves
an explicit solution of the first non-trivial loop equation, relating the
spherical free energy to that of the non-orientable surfaces with topology
.Comment: 13 pages; v2: minor typos, one equation adde
Decay of charged scalar field around a black hole: quasinormal modes of R-N, R-N-AdS and dilaton black holes
It is well known that the charged scalar perturbations of the
Reissner-Nordstrom metric will decay slower at very late times than the neutral
ones, thereby dominating in the late time signal. We show that at the stage of
quasinormal ringing, on the contrary, the neutral perturbations will decay
slower for RN, RNAdS and dilaton black holes. The QN frequencies of the nearly
extreme RN black hole have the same imaginary parts (damping times) for charged
and neutral perturbations. An explanation of this fact is not clear but,
possibly, is connected with the Choptuik scaling.Comment: 10 pages, LaTeX, 4 figures, considerable changes made and wrong
interpretation of computations correcte
Determinant representation for some transition probabilities in the TASEP with second class particles
We study the transition probabilities for the totally asymmetric simple
exclusion process (TASEP) on the infinite integer lattice with a finite, but
arbitrary number of first and second class particles. Using the Bethe ansatz we
present an explicit expression of these quantities in terms of the Bethe wave
function. In a next step it is proved rigorously that this expression can be
written in a compact determinantal form for the case where the order of the
first and second class particles does not change in time. An independent
geometrical approach provides insight into these results and enables us to
generalize the determinantal solution to the multi-class TASEP.Comment: Minor revision; journal reference adde
Dirac quasinormal modes of the Reissner-Nordstr\"om de Sitter black hole
The quasinormal modes of the Reissner-Nordstr\"om de Sitter black hole for
the massless Dirac fields are studied using the P\"oshl-Teller potential
approximation. We find that the magnitude of the imaginary part of the
quasinormal frequencies decreases as the cosmological constant or the orbital
angular momentum increases, but it increases as the charge or the overtone
number increases. An interesting feature is that the imaginary part is almost
linearly related to the real part as the cosmological constant changes for
fixed charge, and the linearity becomes better as the orbital angular momentum
increases. We also prove exactly that the Dirac quasinormal frequencies are the
same for opposite chirality.Comment: 10 pages, 6 figures, Phys. Rev. D in pres
On the Two Species Asymmetric Exclusion Process with Semi-Permeable Boundaries
We investigate the structure of the nonequilibrium stationary state (NESS) of
a system of first and second class particles, as well as vacancies (holes), on
L sites of a one-dimensional lattice in contact with first class particle
reservoirs at the boundary sites; these particles can enter at site 1, when it
is vacant, with rate alpha, and exit from site L with rate beta. Second class
particles can neither enter nor leave the system, so the boundaries are
semi-permeable. The internal dynamics are described by the usual totally
asymmetric exclusion process (TASEP) with second class particles. An exact
solution of the NESS was found by Arita. Here we describe two consequences of
the fact that the flux of second class particles is zero. First, there exist
(pinned and unpinned) fat shocks which determine the general structure of the
phase diagram and of the local measures; the latter describe the microscopic
structure of the system at different macroscopic points (in the limit L going
to infinity in terms of superpositions of extremal measures of the infinite
system. Second, the distribution of second class particles is given by an
equilibrium ensemble in fixed volume, or equivalently but more simply by a
pressure ensemble, in which the pair potential between neighboring particles
grows logarithmically with distance. We also point out an unexpected feature in
the microscopic structure of the NESS for finite L: if there are n second class
particles in the system then the distribution of first class particles
(respectively holes) on the first (respectively last) n sites is exchangeable.Comment: 28 pages, 4 figures. Changed title and introduction for clarity,
added reference
Quasinormal modes from potentials surrounding the charged dilaton black hole
We clarify the purely imaginary quasinormal frequencies of a massless scalar
perturbation on the 3D charged-dilaton black holes. This case is quite
interesting because the potential-step appears outside the event horizon
similar to the case of the electromagnetic perturbations on the large
Schwarzschild-AdS black holes. It turns out that the potential-step type
provides the purely imaginary quasinormal frequencies, while the
potential-barrier type gives the complex quasinormal modes.Comment: 19 pages, 8 figure
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
Exact Superpotentials, Theories with Flavor and Confining Vacua
In this paper we study some interesting properties of the effective
superpotential of N=1 supersymmetric gauge theories with fundamental matter,
with the help of the Dijkgraaf--Vafa proposal connecting supersymmetric gauge
theories with matrix models.
We find that the effective superpotential for theories with N_f fundamental
flavors can be calculated in terms of quantities computed in the pure (N_f=0)
gauge theory. Using this property we compute in a remarkably simple way the
exact effective superpotential of N=1 supersymmetric theories with fundamental
matter and gauge group SU(N_c), at the point in the moduli space where a
maximal number of monopoles become massless (confining vacua). We extend the
analysis to a generic point of the moduli space, and show how to compute the
effective superpotential in this general case.Comment: 16 pages, no figure
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