18,583 research outputs found
Super-bunched bright squeezed vacuum state
In this paper we experimentally study the statistical properties of a bright
squeezed vacuum state containing up to 10^13 photons per mode (10 uJ per
pulse), produced via high gain parametric down conversion (PDC). The effects of
bunching and superbunching of photons were observed for a single mode PDC
radiation by second-order intensity correlation function measurements with
analog detectors.Comment: 4 pages, 3 figures, submitted to Optics Letter
Statistics of speckle patterns
We develop a general method for calculating statistical properties of the
speckle pattern of coherent waves propagating in disordered media. In some
aspects this method is similar to the Boltzmann-Langevin approach for the
calculation of classical fluctuations. We apply the method to the case where
the incident wave experiences many small angle scattering events during
propagation, but the total angle change remains small. In many aspects our
results for this case are different from results previously known in the
literature. The correlation function of the wave intensity at two points
separated by a distance , has a long range character. It decays as a power
of and changes sign. We also consider sensitivities of the speckles to
changes of external parameters, such as the wave frequency and the incidence
angle.Comment: 4 pages, 2 figure
Minimizing movements for mean curvature flow of droplets with prescribed contact angle
We study the mean curvature motion of a droplet flowing
by mean curvature on a horizontal
hyperplane with a possibly nonconstant prescribed contact angle.
Using the solutions constructed as a limit of an approximation
algorithm of
Almgren-Taylor-Wang and Luckhaus-Sturzenhecker,
we show the existence of
a weak evolution, and its compatibility with a distributional
solution. We also prove various comparison results
Minimizing movements for mean curvature flow of droplets with prescribed contact angle
We study the mean curvature motion of a droplet flowing
by mean curvature on a horizontal
hyperplane with a possibly nonconstant prescribed contact angle.
Using the solutions constructed as a limit of an approximation
algorithm of
Almgren-Taylor-Wang and Luckhaus-Sturzenhecker,
we show the existence of
a weak evolution, and its compatibility with a distributional
solution. We also prove various comparison results
Minimizing movements for mean curvature flow of droplets with prescribed contact angle
We study the mean curvature motion of a droplet flowing
by mean curvature on a horizontal
hyperplane with a possibly nonconstant prescribed contact angle.
Using the solutions constructed as a limit of an approximation
algorithm of
Almgren-Taylor-Wang and Luckhaus-Sturzenhecker,
we show the existence of
a weak evolution, and its compatibility with a distributional
solution. We also prove various comparison results
New data on the distribution of fungus gnats (Diptera: Bolitophilidae, Keroplatidae) in Tyva Republic (Russia, Siberia)
Аn annotated list is given and the distribution of 13 species of fungus gnats of the families Bolitophilidae and Keroplatidae, collected from Tuva in Eastern Siberia, is provided. As a result of our study, 11 species were added to the list of fungus gnats of Tuv
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