Issue 4, 2001
Nonlinear optics of gaseous media: breakthrough into ultrashort pulse region and use of new spectral regions
Nonlinear optics of gaseous media: breakthrough into ultrashort pulse region and use of new spectral regions
A.M. Zhel!ikov
New research trends in modern physics that have emerged due to progress in ideas and technology based on studies and use of nonlinear optical processes in excited and ionized gaseous media are discussed. An outlook of the use of these processes for frequency conversion, ultrashort pulses generation and development of new methods of nonlinear spectroscopy and nonlinear optical analysis is given.
Show AbstractThe gravitational mass defect
The gravitational mass defect
Yu.M. Loskutov
A covariant approach to the definition of the gravitational mass defect is proposed. The system of gravitational field equations is supplemented by an equation for the mass of a body. A spherically symmetric static problem of the island type is considered as an example, and it is shown that, due to the gravitational mass defect, twice the mass of the body in a volume of arbitrary radius (in standard coordinates) is always less than this radius. Some other consequences are considered.
Show AbstractQuark energy in a three-dimensional QCD model with a constant background field
Quark energy in a three-dimensional QCD model with a constant background field
V.Ch. Zhukovskii, N.A. Peskov, S.A. Denisov
In an $SU(2)$ Yang-Mills field model with a topological mass $\theta$ in the space with dimensionality $d=2+1$ and with account for an external background field, the one-loop quark energy correction is calculated. As a background field, the exact constant solutions of the Yang-Mills field equations are chosen. It is shown that, at the quark mass $m=\frac{1}{4}\theta$, the effective quark mass remains equal to zero even when the calculated one-loop vacuum correction is taken into account. This fact may be caused by a certain internal symmetry of the set of the background gauge field solutions (constant non-Abelian fields) and solutions of the Dirac equation in these fields.
Show AbstractSelf-adjoint Hamiltonians of scalar fields in the Schwarzschild metric
Self-adjoint Hamiltonians of scalar fields in the Schwarzschild metric
Ch. Aphantitis, S.V. Kalyashin
It is shown that, in a space with Schwarzschild metric, the Hamiltonian of a massless scalar field admits a self-adjoint extension.
Show AbstractEstimating the end effects in heating a cylindrical sample in a finite solenoid
Estimating the end effects in heating a cylindrical sample in a finite solenoid
R.V. Budnik, V.B. Glasko
A two-dimensional problem of heating steel cylindrical samples in a solenoidal inductor has been considered. Thickness of a layer heated to temperatures required for subsequent hardening has been numerically estimated.
Show AbstractDetecting weak gravitational pulses against the anomalous noise background
Detecting weak gravitational pulses against the anomalous noise background
A.V. Gusev, A.Yu. Kochetkova, V.N. Rudenko
A locally optimal algorithm for detecting weak and infrequent gravitational pulses based on considering additive noise at the output from resonance gravitational antennas as a narrow-band process with anomalous noise and the Gaussian + Laplace distribution is proposed.
Show AbstractHydrodynamic instability of a planar flame front in a gas for low-frequency perturbations at arbitrary Lewis numbers
Hydrodynamic instability of a planar flame front in a gas for low-frequency perturbations at arbitrary Lewis numbers
A.V. Uvarov, E.A. Savchenkova, A.I. Osipov
The problem of combustion wave stability under conditions where the wellknown Landau-Darrieus theory does not apply is solved. The applicability limits of the Landau-Darrieus theory are determined.
Show AbstractCluster speckle structures and Gabor's information diagram
Cluster speckle structures and Gabor's information diagram
Yu.V. Vasil'ev, A.V. Kozar', E.F. Kuritsyna, A.E. Luk'yanov
Formation of cluster speckle structures in reflecting diffraction of the Gaussian beam of coherent radiation illuminating the anisotropically rough surface of a narrow metal strip has been experimentally detected. On the basis of information treatment of Gabor's diffraction phenomena in optics, the physical nature of the speckle cluster structure has been explained.
Show AbstractThe high-temperature Staebler-Wronski effect in undoped high-resistance $a$-Si:H films
The high-temperature Staebler-Wronski effect in undoped high-resistance $a$-Si:H films
I.A. Kurova, N.N. Ormont
At temperatures $T>400$ K the anomalous Staebler-Wronski effect in undoped high-resistance $a$-Si:H films, a monotonous increase in dark conductivity and photo conductivity on illumination and nonmonotonous variation of conductivity after illumination, has been detected. Nonmonotonous relaxation of conductivity is described by the sum of two extended exponential curves with different parameters $\tau$ and $E$. It has been shown that the detected effect can be explained by the formation of two types of metastable states, the broken bonds in silicon and electrically active atoms of uncontrolled donor impurity.
Show AbstractThe effect of turbulence on small solid particles in water suspension
The effect of turbulence on small solid particles in water suspension
Yu.G. Pyrkin, V.P. Petrov, I.N. Ivanova, M.A. Silaev
Interaction of tiny water-suspended particles with turbulence created by a vibrating grating is experimentally investigated. The difference between the pulsation dispersion of the flow velocity magnitude in pure water and in the suspension and the key energy parameters of solid particles are compared.
Show AbstractNonplanar trajectories of motion of a spacecraft with a current element in the gravitational and magnetic fields of the Earth
Nonplanar trajectories of motion of a spacecraft with a current element in the gravitational and magnetic fields of the Earth
V.I. Denisov, V.B. Pinchuk
An exact solution to the nonlinear equations describing the spacecraft motion in a nonplanar trajectory under the action of tbe ampere and gravitational-field forces is found.
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