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 AbstractA 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 AbstractIn 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 AbstractIt is shown that, in a space with Schwarzschild metric, the Hamiltonian of a massless scalar field admits a self-adjoint extension.
Show AbstractA 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 AbstractA 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 AbstractThe 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 AbstractFormation 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 AbstractAt 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 AbstractInteraction 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 AbstractAn 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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