14,513 research outputs found
The Southern Vilnius Photometric System. IV. The E Regions Standard Stars
This paper is the fourth in a series on the extension of the Vilnius
photometric system to the southern hemisphere. Observations were made of 60
stars in the Harvard Standard E regions to increase a set of standard stars.Comment: 6 pages, TeX, requires 2 macros (baltic2.tex, baltic4.tex) included
no figures, to be published in Baltic Astronomy, Vol 6, pp1-6 (1997
Nonlinear Band Gap Transmission in Optical Waveguide Arrays
The effect of nonlinear transmission in coupled optical waveguide arrays is
theoretically investigated via numerical simulations on the corresponding model
equations. The realistic experimental setup is suggested injecting the beam in
a single boundary waveguide, linear refractive index of which () is larger
than one () of other identical waveguides in the array. Particularly, the
effect holds if , where is a linear coupling constant
between array waveguides, is a carrier wave frequency and is a
light velocity. Making numerical experiments in case of discrete nonlinear
Schr\"odinger equation it is shown that the energy transfers from the boundary
waveguide to the waveguide array above certain threshold intensity of the
injected beam. This effect is explained by means of the creation and
propagation of gap solitons in full analogy with the similar phenomenon of
nonlinear supratransmission [F. Geniet, J. Leon, PRL, {\bf 89}, 134102, (2002)]
in case of discrete sine-Gordon lattice.Comment: 4 pages, 6 figures. Phys. Rev. Lett. (in press
A simple operational interpretation of the fidelity
This note presents a corollary to Uhlmann's theorem which provides a simple
operational interpretation for the fidelity of mixed states.Comment: 1 pag
Downsizing a Great Observatory: Reinventing Spitzer in the Warm Mission
The Spitzer Space Telescope transitioned from the cryogen mission to the IRAC warm mission during 2009. This transition involved changing several areas of operations in order to cut the mission annual operating costs to 1/3 of the cryogen mission amount. In spite of this substantial cut back, Spitzer continues to have one of the highest science return per dollar ratio of any of NASA's extended missions. This paper will describe the major operational changes made for the warm mission and how they affect the science return. The paper will give several measures showing that warm Spitzer continues as one of the most scientifically productive mission in NASA's portfolio. This work was performed at the California Institute of Technology under contract to the National Aeronautics and Space Administration
Application of Dressing Method for Long Wave-Short Wave Resonance Interaction Equation
In this paper we investigate the application of Zakharov - Shabat dressing
method to (2+1) - dimensional long wave - short wave resonance interaction
equation (LSRI). Using this method we can construct the exact N - soliton
solution of this equation depending on arbitrary constants. It contains both
solutions which don't decay along N different directions in space infinity, and
"dromion" ones, or localized solutions that decay exponentially in all
directions.Comment: 8 page
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