On the third critical field in Ginzburg-Landau theory

Using recent results by the authors on the spectral asymptotics of the Neumann Laplacian with magnetic field, we give precise estimates on the critical field, $H_{C_3}$, describing the appearance of superconductivity in superconductors of type II. Furthermore, we prove that the local and global definitions of this field coincide. Near $H_{C_3}$ only a small part, near the boundary points where the curvature is maximal, of the sample carries superconductivity. We give precise estimates on the size of this zone and decay estimates in both the normal (to the boundary) and parallel variables

Spectrums of Black Hole in de Sitter Spacetime with Highly Damped Quasinormal Modes: High Overtone Case

Motivated by recent physical interpretation on quasinormal modes presented by Maggiore, the adiabatic quantity method given by Kunstatter is used to calculate the spectrums of a non-extremal Schwarzschild de Sitter black hole in this paper, as well as electrically charged case. According to highly damped Konoplya and Zhidenko's numerical observational results for high overtone modes\cite{Konoplya}, we found that the asymptotic non-flat spacetime structure leads two interesting facts as followings: (i) near inner event horizon, the area and entropy spectrums, which are given by $A_{en} = 8 n_1 \pi \hbar$, $S_{en} = 2\pi n_1\hbar$, are equally spaced accurately. (ii) However, near outer cosmological horizon the spectrums, which are in the form of $A_{cn} = 16 n_2 \pi \hbar - \sqrt{\frac{48\pi}{\Lambda}A_{cn} - 3 A_{cn}^2}$, $S_{cn} = 4 \pi n_2 \hbar - \sqrt{\frac{3\pi}{\Lambda}A_{cn} - 3/16 A_{cn}^2}$, are not markedly equidistant. Finally, we also discuss the electrically charged case and find the black holes in de Sitter spacetime have similar quantization behavior no matter with or without charge.Comment: 12 pages, 2 firures, published versio

Dislocation constriction and cross-slip in Al and Ag: an ab initio study

A novel model based on the Peierls framework of dislocations is developed. The new theory can deal with a dislocation spreading at more than one slip planes. As an example, we study dislocation cross-slip and constriction process of two fcc metals, Al and Ag. The energetic parameters entering the model are determined from ab initio calculations. We find that the screw dislocation in Al can cross-slip spontaneously in contrast with that in Ag, which splits into partials and cannot cross-slip without first being constricted. The dislocation response to an external stress is examined in detail. We determine dislocation constriction energy and critical stress for cross-slip, and from the latter, we estimate the cross-slip energy barrier for the straight screw dislocations

Simultaneous Inference of User Representations and Trust

Inferring trust relations between social media users is critical for a number of applications wherein users seek credible information. The fact that available trust relations are scarce and skewed makes trust prediction a challenging task. To the best of our knowledge, this is the first work on exploring representation learning for trust prediction. We propose an approach that uses only a small amount of binary user-user trust relations to simultaneously learn user embeddings and a model to predict trust between user pairs. We empirically demonstrate that for trust prediction, our approach outperforms classifier-based approaches which use state-of-the-art representation learning methods like DeepWalk and LINE as features. We also conduct experiments which use embeddings pre-trained with DeepWalk and LINE each as an input to our model, resulting in further performance improvement. Experiments with a dataset of $\sim$356K user pairs show that the proposed method can obtain an high F-score of 92.65%.Comment: To appear in the proceedings of ASONAM'17. Please cite that versio

EFFECTS OF HIGH AND LOW MANAGEMENT INTENSITY ON PROFITABILITY FOR THREE WATERMELON GENOTYPES

A replicated, small plot study on watermelon [Citrullus lanatus (Thunberg) Matsumura and Nakai] in 1997, 1999, and 2000 revealed that production management intensity affected yields and profitability of watermelon, in Oklahoma. Management intensity was based on a combination of cultural practices and levels of use of production methods. Low intensity management (LM) consisted of use of soil fertilization and weed control. High intensity management (HM) included the same weed control and fertilization as LM but also included use of plastic mulch, drip irrigation, insect pest control, and plant disease control. Cost and return analyses were based on the range of actual prices during the cropping season and the range of yields during the three years. Yields from the seedless triploid genotype 'Gem Dandy' consistently resulted in greater positive net revenue under HM than the diploid open pollinated 'Allsweet' or the hybrid diploid 'Sangria'. Under LM, yields from the seedless triploid also resulted in greater net revenues when conditions were favorable or lost less money than the open pollinated 'Allsweet' or the hybrid diploid 'Sangria' when conditions were unfavorable.Crop Production/Industries,

Strain-stress study of AlxGa1-xN/AlN heterostructures on c-plane sapphire and related optical properties

This work presents a systematic study of stress and strain of AlxGa1-xN/AlN with composition ranging from GaN to AlN, grown on a c-plane sapphire by metal-organic chemical vapor deposition, using synchrotron radiation high-resolution X-ray diffraction and reciprocal space mapping. The c-plane of the AlxGa1-xN epitaxial layers exhibits compressive strain, while the a-plane exhibits tensile strain. The biaxial stress and strain are found to increase with increasing Al composition, although the lattice mismatch between the AlxGa1-xN and the buffer layer AlN gets smaller. A reduction in the lateral coherence lengths and an increase in the edge and screw dislocations are seen as the AlxGa1-xN composition is varied from GaN to AlN, exhibiting a clear dependence of the crystal properties of AlxGa1-xN on the Al content. The bandgap of the epitaxial layers is slightly lower than predicted value due to a larger tensile strain effect on the a-axis compared to the compressive strain on the c-axis. Raman characteristics of the AlxGa1-xN samples exhibit a shift in the phonon peaks with the Al composition. The effect of strain is also discussed on the optical phonon energies of the epitaxial layers. The techniques discussed here can be used to study other similar materials.Comment: 14 pages, 5 figures, 2 table

Time variable cosmological constant of holographic origin with interaction in Brans-Dicke theory

Time variable cosmological constant (TVCC) of holographic origin with interaction in Brans-Dicke theory is discussed in this paper. We investigate some characters for this model, and show the evolutions of deceleration parameter and equation of state (EOS) for dark energy. It is shown that in this scenario an accelerating universe can be obtained and the evolution of EOS for dark energy can cross over the boundary of phantom divide. In addition, a geometrical diagnostic method, jerk parameter is applied to this model to distinguish it with cosmological constant.Comment: 10 pages, 9 figure

The Relationship Between Galaxies and Low Redshift Weak Lyman alpha Absorbers in the Directions of H1821+643 and PG1116+215

To study the nature of low z Lya absorbers in the spectra of QSOs, we have obtained high signal-to-noise UV spectra of H 1821+643 (z = 0.297) and PG 1116+215 (z = 0.177) with the GHRS on the HST. The spectra have minimum S/N of 70-100 and 3 sigma limiting equivalent widths of 50-75 mA. We detect 26 Lya lines with Wr > 50 mA toward H1821+643 and 13 toward PG1116+215, which implies a density of 102+/-16 lines per unit redshift. The two-point correlation function shows marginal evidence of clustering on ~500 km/s scales, but only if the weakest lines are excluded. We have also used the WIYN Observatory to measure galaxy redshifts in the ~1 degree fields centered on each QSO. We find 17 galaxy-absorber pairs within projected distances of 1 Mpc with velocity separations of 350 km/s or less. Monte Carlo simulations show that if the Lya lines are randomly distributed, the probability of observing this many close pairs is 3.6e-5. We find that all galaxies with projected distances of 600 kpc or less have associated Lya absorbers within 1000 km/s, and the majority of these galaxies have absorbers within 350 km/s. We also find that the Lya equivalent width is anticorrelated with the projected distance of the nearest galaxy out to at least 600 kpc, but this should be interpreted cautiously because there are potential selection biases. Statistical tests using the entire sample also indicate that the absorbers are not randomly distributed. We discuss the nature of the Lya absorbers in light of the new data.Comment: Accepted for publication in ApJ. 17 pages plus 11 tables and 17 figure

Brownian motion of solitons in a Bose-Einstein Condensate

For the first time, we observed and controlled the Brownian motion of solitons. We launched solitonic excitations in highly elongated $^{87}\rm{Rb}$ BECs and showed that a dilute background of impurity atoms in a different internal state dramatically affects the soliton. With no impurities and in one-dimension (1-D), these solitons would have an infinite lifetime, a consequence of integrability. In our experiment, the added impurities scatter off the much larger soliton, contributing to its Brownian motion and decreasing its lifetime. We describe the soliton's diffusive behavior using a quasi-1-D scattering theory of impurity atoms interacting with a soliton, giving diffusion coefficients consistent with experiment.Comment: 4 figure

U-duality (sub-)groups and their topology

We discuss some consequences of the fact that symmetry groups appearing in compactified (super-)gravity may be non-simply connected. The possibility to add fermions to a theory results in a simple criterion to decide whether a 3-dimensional coset sigma model can be interpreted as a dimensional reduction of a higher dimensional theory. Similar criteria exist for higher dimensional sigma models, though less decisive. Careful examination of the topology of symmetry groups rules out certain proposals for M-theory symmetries, which are not ruled out at the level of the algebra's. We conclude with an observation on the relation between the ``generalized holonomy'' proposal, and the actual symmetry groups resulting from E_10 and E_11 conjectures.Comment: LaTeX, 8 pages, 2 tables, 1 figure, uses IOP-style files. Contributed to the proceedings of the RTN-workshop ``The quantum structure of space-time and the geometrical nature of the fundamental interactions,'', Copenhagen, Denmark, september 200