5,374 research outputs found
Scaling Analysis of Domain-Wall Free-Energy in the Edwards-Anderson Ising Spin Glass in a Magnetic Field
The stability of the spin-glass phase against a magnetic field is studied in
the three and four dimensional Edwards-Anderson Ising spin glasses. Effective
couplings and effective fields associated with length scale L are measured by a
numerical domain-wall renormalization group method. The results obtained by
scaling analysis of the data strongly indicate the existence of a crossover
length beyond which the spin-glass order is destroyed by field H. The crossover
length well obeys a power law of H which diverges as H goes to zero but remains
finite for any non-zero H, implying that the spin-glass phase is absent even in
an infinitesimal field. These results are well consistent with the droplet
theory for short-range spin glasses.Comment: 4 pages, 5 figures; The text is slightly changed, the figures 3, 4
and 5 are changed, and a few references are adde
Gravitino and Axino SuperWIMPs
Gravitinos and axinos produced in the late decays of other supersymmetric
particles are well-motivated dark matter (DM) candidates, whose experimental
evidences are very distinctive and different from other standard candidates, as
thermal produced neutralinos in similar supersymmetric models. In particular,
charged sleptons could appear stable because of the length of its lifetime. The
direct production of such particles at both the Large Hadron Collider (LHC) and
a future International Linear Collider (ILC) can give not only a clear
signature of supersymmetry but also the first non-gravitational evidence of
dark matter.Comment: 4 pages, LaTeX, 1 figure, Updated references. To appear in
Proceedings of SUSY06, the 14th International Conference on Supersymmetry and
the Unification of Fundamental Interactions, UC Irvine, California, 12-17
June 200
Automatic normal orientation in point clouds of building interiors
Orienting surface normals correctly and consistently is a fundamental problem
in geometry processing. Applications such as visualization, feature detection,
and geometry reconstruction often rely on the availability of correctly
oriented normals. Many existing approaches for automatic orientation of normals
on meshes or point clouds make severe assumptions on the input data or the
topology of the underlying object which are not applicable to real-world
measurements of urban scenes. In contrast, our approach is specifically
tailored to the challenging case of unstructured indoor point cloud scans of
multi-story, multi-room buildings. We evaluate the correctness and speed of our
approach on multiple real-world point cloud datasets
Bubbling 1/2 BPS Geometries and Penrose Limits
We discuss how to take a Penrose limit in bubbling 1/2 BPS geometries at the
stage of a single function z(x_1,x_2,y). By starting from the z of the AdS_5 x
S^5 we can directly derive that of the pp-wave via the Penrose limit. In that
time the function z for the pp-wave with 1/R^2-corrections is obtained. We see
that it surely reproduces the pp-wave with 1/R^2 terms. In addition we consider
the Penrose limit in the configuration of the concentric rings.Comment: 15 pages, 3 figures, LaTeX, v2:higher order corrections are added,
typos corrected and references added, version to appear in PR
Optical phonons in new ordered perovskite Sr2Cu(Re0.69Ca0.31) Oy system observed by infrared reflectance spectroscopy
We report infrared reflectivity spectra for a new correlated cupric oxide
system Sr2Cu(Re0.69Ca0.31)Oy with y ~ 0.6 at several temperatures ranging
between 8 and 380 K. The reflectivity spectrum at 300 K comprises of several
optical phonons. A couple of residual bands located around 315 and 653 cm-1
exhibit exceptionally large intensity as compared to the other ones. The
overall reflectivity spectrum lifts up slightly with increasing temperature.
The energy and damping factor of transverse-optical phonons are determined by
fitting the imaginary dielectric constant by Lorentz oscillator model and
discussed as a function of temperature in terms of lattice anharmonicity.Comment: 9 pages, 3 figures, presented at ISS2005, to appear in Physica
Single Impurity Anderson Model with Coulomb Repulsion between Conduction Electrons on the Nearest-Neighbour Ligand Orbital
We study how the Kondo effect is affected by the Coulomb interaction between
conduction electrons on the basis of a simplified model. The single impurity
Anderson model is extended to include the Coulomb interaction on the
nearest-neighbour ligand orbital. The excitation spectra are calculated using
the numerical renormalization group method. The effective bandwidth on the
ligand orbital, , is defined to classify the state. This quantity
decreases as the Coulomb interaction increases. In the
region, the low energy properties are described by the Kondo state, where
is the hybridization width. As decreases in this region, the
Kondo temperature is enhanced, and its magnitude becomes comparable to
for . In the region, the local
singlet state between the electrons on the and ligand orbitals is formed.Comment: 5 pages, 3 figures, LaTeX, to be published in J. Phys. Soc. Jpn Vol.
67 No.
Is Karenia a synonym of Asterodinium-Brachidinium (Gymnodiniales, Dinophyceae)?
From material collected in open waters of the NW and Equatorial Pacific Ocean the detailed morphology of brachidiniaceans based on two specimens of Asterodinium gracile is reported for the first time. SEM observations showed that the straight apical groove, the
morphological characters and orientation of the cell body were similar to those described for species of Karenia. Brachidinium and Asterodinium showed high morphological variability in the length of the extensions and intermediate specimens with Karenia. Karenia-like cells that strongly resemble Brachidinium and Asterodinium but lacking the extensions co-occurred with the typical specimens. The life cycle and morphology of Karenia papilionacea should be investigated under natural conditions because of the strong similarity
with the brachidiniaceans
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