11,798 research outputs found
Failure criterion of glass fabric reinforced plastic laminates
Failure criteria are derived for several modes of failure (in unaxial tensile or compressive loading, or biaxial combined tensile-compressive loading) in the case of closely woven plain fabric, coarsely-woven plain fabric, or roving glass cloth reinforcements. The shear strength in the interaction formula is replaced by an equation dealing with tensile or compressive strength in the direction making a 45 degree angle with one of the anisotropic axes, for the uniaxial failure criteria. The interaction formula is useful as the failure criterion in combined tension-compression biaxial failure for the case of closely woven plain fabric laminates, but poor agreement is obtained in the case of coarsely woven fabric laminates
Two quantum analogues of Fisher information from a large deviation viewpoint of quantum estimation
We discuss two quantum analogues of Fisher information, symmetric logarithmic
derivative (SLD) Fisher information and Kubo-Mori-Bogoljubov (KMB) Fisher
information from a large deviation viewpoint of quantum estimation and prove
that the former gives the true bound and the latter gives the bound of
consistent superefficient estimators. In another comparison, it is shown that
the difference between them is characterized by the change of the order of
limits.Comment: LaTeX with iopart.cls, iopart12.clo, iopams.st
Poincar\'{e} gauge theory of gravity
A Poincar\'{e} gauge theory of (2+1)-dimensional gravity is developed.
Fundamental gravitational field variables are dreibein fields and Lorentz gauge
potentials, and the theory is underlain with the Riemann-Cartan space-time. The
most general gravitational Lagrangian density, which is at most quadratic in
curvature and torsion tensors and invariant under local Lorentz transformations
and under general coordinate transformations, is given. Gravitational field
equations are studied in detail, and solutions of the equations for weak
gravitational fields are examined for the case with a static, \lq \lq spin"less
point like source. We find, among other things, the following: (1)Solutions of
the vacuum Einstein equation satisfy gravitational field equations in the
vacuum in this theory. (2)For a class of the parameters in the gravitational
Lagrangian density, the torsion is \lq \lq frozen" at the place where \lq \lq
spin" density of the source field is not vanishing. In this case, the field
equation actually agrees with the Einstein equation, when the source field is
\lq \lq spin"less. (3)A teleparallel theory developed in a previous paper is
\lq \lq included as a solution" in a limiting case. (4)A Newtonian limit is
obtainable, if the parameters in the Lagrangian density satisfy certain
conditions.Comment: 27pages, RevTeX, OCU-PHYS-15
Plane torsion waves in quadratic gravitational theories
The definition of the Riemann-Cartan space of the plane wave type is given.
The condition under which the torsion plane waves exist is found. It is
expressed in the form of the restriction imposed on the coupling constants of
the 10-parametric quadratic gravitational Lagrangian. In the mathematical
appendix the formula for commutator of the variation operator and Hodge
operator is proved. This formula is applied for the variational procedure when
the gravitational field equations are obtained in terms of the exterior
differential forms.Comment: 3 May 1998. - 11
On the Decoupling of the Homogeneous and Inhomogeneous Parts in Inhomogeneous Quantum Groups
We show that, if there exists a realization of a Hopf algebra in a
-module algebra , then one can split their cross-product into the tensor
product algebra of itself with a subalgebra isomorphic to and commuting
with . This result applies in particular to the algebra underlying
inhomogeneous quantum groups like the Euclidean ones, which are obtained as
cross-products of the quantum Euclidean spaces with the quantum groups
of rotation of , for which it has no classical analog.Comment: Latex file, 27 pages. Final version to appear in J. Phys.
Gravitational Shock Waves for Schwarzschild and Kerr Black Holes
The metrics of gravitational shock waves for a Schwarzschild black hole in
ordinary coordinates and for a Kerr black hole in Boyer-Lindquist coordinates
are derived. The Kerr metric is discussed for two cases: the case of a Kerr
black hole moving parallel to the rotational axis, and moving perpendicular to
the rotational axis. Then, two properties from the derived metrics are
investigated: the shift of a null coordinate and the refraction angle crossing
the gravitational shock wave. Astrophysical applications for these metrics are
discussed in short.Comment: 24 Pages, KOBE--FHD--93--03, {\LaTeX
Evidence for Non-Hydrostatic Gas from the Cluster X-ray to Lensing Mass Ratio
Using a uniform analysis procedure, we measure spatially resolved weak
gravitational lensing and hydrostatic X-ray masses for a sample of 18 clusters
of galaxies. We find a radial trend in the X-ray to lensing mass ratio: at
r2500 we obtain a ratio MX/ML=1.03+/-0.07 which decreases to MX/ML=0.78+/-0.09
at r500. This difference is significant at 3 sigma once we account for
correlations between the measurements. We show that correcting the lensing mass
for excess correlated structure outside the virial radius slightly reduces, but
does not eliminate this trend. An X-ray mass underestimate, perhaps due to
nonthermal pressure support, can explain the residual trend. The trend is not
correlated with the presence or absence of a cool core. We also examine the
cluster gas fraction and find no correlation with ML, an important result for
techniques that aim to determine cosmological parameters using the gas
fraction.Comment: 8 pages, minor modifications, accepted for publication in MNRA
Diamagnetic effects, Impulsive Alfven waves, Cavity etc, stemming from the busing of bi-directional flow burst and energetic ion injections in nighttime magnetosphere
第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月16日(水) 統計数理研究所 セミナー室
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