7,286 research outputs found
The evaluation of liquefaction potential of oil-containing sand under cyclic loading
Risk and Reliability in Geotechnical Engineerin
Magnetic light
In this paper we report on the observation of novel and highly unusual
magnetic state of light. It appears that in small holes light quanta behave as
small magnets so that light propagation through such holes may be affected by
magnetic field. When arrays of such holes are made, magnetic light of the
individual holes forms novel and highly unusual two-dimensional magnetic light
material. Magnetic light may soon become a great new tool for quantum
communication and computing.Comment: Submitted to Phys.Rev.Lett., 3 figure
Abelian Dyons in the Maximal Abelian Projection of SU(2) Gluodynamics
Correlations of the topological charge Q, the electric current J^e and the
magnetic current J^m in SU(2) lattice gauge theory in the Maximal Abelian
projection are investigated. It occurs that the correlator > is
nonzero for a wide range of values of the bare charge. It is shown that: (i)
the abelian monopoles in the Maximal Abelian projection are dyons which carry
fluctuating electric charge; (ii) the sign of the electric charge e(x)
coincides with that of the product of the monopole charge m(x) and the
topological charge density Q(x).Comment: 6 pages, 2 EPS figures, LaTeX, uses epsf.sty; revision: minor
corrections, references adde
Non-linear Weibel-type Soliton Modes
Discussion is given of non-linear soliton behavior including coupling between
electrostatic and electromagnetic potentials for non-relativistic, weakly
relativistic, and fully relativistic plasmas. For plasma distribution functions
that are independent of the canonical momenta perpendicular to the soliton
spatial structure direction there are, in fact, no soliton behaviors allowed
because transverse currents are zero. Dependence on the transverse canonical
momenta is necessary. When such is the case, it is shown that the presence or
absence of a soliton is intimately connected to the functional form assumed for
the particle distribution functions. Except for simple situations, the coupled
non-linear equations for the electrostatic and electromagnetic potentials would
seem to require numerical solution procedures. Examples are given to illustrate
all of these points for non-relativistic, weakly relativistic, and fully
relativistic plasmas.Comment: Accepted for publication at Journal of Physics A: Mathematical and
Theoretica
Interpretation of Kerr Microscopic Domain Contrast on Curved Surfaces
In this letter, we address a technical peculiarity of wide-field magneto-optical Kerr microscopy, which may easily lead to a misinterpretation of the domain contrast on curved surfaces. On the example of circumferentially magnetized domains in ferromagnetic microwires, we show that the checkerboard domain pattern, which typically shows up in polar Kerr sensitivity, is caused by the superposition of longitudinal Kerr contrasts that arise from in-plane magnetization components and inclined light incidence rather than from the magnetization components perpendicular to the focal plane as claimed in the literature. Experimental ways to avoid such peculiar contrasts are demonstrated. © 2010-2012 IEEE.Boehringer IngelheimThe study was supported financially by Boehringer Ingelheim International GmbH
The Hubble Diagram to Redshift >6 from 69 Gamma-Ray Bursts
One of the few ways to measure the properties of Dark Energy is to extend the
Hubble daigram (HD) to higher redshifts with Gamma-Ray Bursts (GRBs). GRBs have
at least five properties (their spectral lag, variability, spectral peak photon
energy, time of the jet break, and the minimum rise time) which have
correlations to the luminosity of varying quality. In this paper, I construct a
GRB HD with 69 GRBs over a redshift range of 0.17 to >6, with half the bursts
having a redshift larger than 1.7. This paper uses over 3.6 times as many GRBs
and 12.7 times as many luminosity indicators as any previous GRB HD work. For
the gravitational lensing and Malmquist biases, I find that the biases are
small, with an average of 0.03 mag and an RMS scatter of 0.14 mag in the
distance modulus. The GRB HD is well-behaved and nicely delineates the shape of
the HD. The reduced chi-square for the fit to the concordance model is 1.05 and
the RMS scatter about the concordance model is 0.65 mag. This accuracy is just
a factor of 2.0 times that gotten for the same measure from all the big
supernova surveys. I fit the GRB HD to a variety of models, including where the
Dark Energy has its equation of state parameter varying as w(z)=w_0 + w_a
z/(1+z). I find that the concordance model is consistent with the data. That
is, the Dark Energy can be described well as a Cosmological Constant that does
not change with time. (abridged)Comment: ApJ in press, 88 pages, 15 figure
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