2,830 research outputs found
One class of linear Fredholm integral equations with functionals and parameters
The theory of linear Fredholm integral-functional equations of the second
kind with linear functionals and with a parameter is considered. The necessary
and sufficient conditions are obtained for the coefficients of the equation and
those parameter values, in the nighbohood of which the equation has solutions.
The leading terms of the asymptotics of the solutions are constructed. The
constructive method is proposed for constructing a solution both in the regular
case and in the irregular one. In the regular case, the solution is constructed
as a Taylor series in powers of the parameter. In the irregular case, the
solution is constructed as a Laurent series in powers of the parameter.
Constructive theory and method is demonstrated on the model example
Supercritical holes for the doubling map
For a map and an open connected set ( a hole) we
define to be the set of points in whose -orbit avoids
. We say that a hole is supercritical if (i) for any hole such
that the set is either empty or contains
only fixed points of ; (ii) for any hole such that \barH\subset H_0
the Hausdorff dimension of is positive.
The purpose of this note to completely characterize all supercritical holes
for the doubling map .Comment: This is a new version, where a full characterization of supercritical
holes for the doubling map is obtaine
Main results of atmospheric fine structure parameter observation in the lower thermosphere
The capabilities of the radiometeor method of wind measurement increase with the increase of the transmitted power of radar stations fitted with goniometric systems which enables the observation of shower meteors along with sporadic background. In shower observations the meteor zone reflecting area narrows to the echo surface which is perpendicular to the flux radiant. Favorable conditions are created for singling out atmospheric disturbances in which the wave front is parallel to the echo surface which plays, in this case, the role of a frequency filter. For the first time this technique allowed wave disturbances with periods of approx. greater than 4 min. to be measured, with about a 99 percent probability of exceeding the level of the turbulence noise, during the Geminid and Perseid showers. Maximum values of such wave disturbance amplitudes were about 15 to 20 m/s, with lifetimes up to 2 hrs
Super Landau Models on Odd Cosets
We construct d=1 sigma models of the Wess-Zumino type on the SU(n|1)/U(n)
fermionic cosets. Such models can be regarded as a particular supersymmetric
extension (with a target space supersymmetry) of the classical Landau model,
when a charged particle possesses only fermionic coordinates. We consider both
classical and quantum models, and prove the unitarity of the quantum model by
introducing the metric operator on the Hilbert space of the quantum states,
such that all their norms become positive-definite. It is remarkable that the
quantum n=2 model exhibits hidden SU(2|2) symmetry. We also discuss the planar
limit of these models. The Hilbert space in the planar n=2 case is shown to
carry SU(2|2) symmetry which is different from that of the SU(2|1)/U(1) model.Comment: 1 + 33 pages, some typos correcte
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