Maps and their properties under periodic actions are considered. Analytical conditions for one-dimensional polymodal maps to have the prescribed dynamics are obtained. The behavior of a family of one-dimensional quadratic maps under parameter perturbations of periods 2 and 3 is numerically studied in detail. The relevant bifurcation diagrams are constructed.
Show AbstractMethods for modeling and computing problems of diffraction on domain walls and vertical Bloch lines of uniax:ial ferromagnetics with cylindrical magnetic domains are analyzed. The three-dimensional boundary-value problem of diffraction of a plane electromagnetic wave on the domain walls and the vertical Bloch lines in ferrite-garnets is considered. In accordance with the method of anisotropic dark-field observation, the solution is sought in the form of the superposition of nondiffracted and magneto-optical parts. The results obtained and experimental data are compared.
Show AbstractLuminosity of a degenerate ultrarelativistic electron gas in a superstrong magnetic field due to photoproduction of axions on electrons is calculated. Comparison of the result obtained with the luminosity induced by photoproduction of neutrino pairs on electrons enabled the relative upper limit of the axion-electron coupling constant $g_{ae}$ to be found.
Show AbstractUsing the canonical normalization condition for the matter superfields and regularization by a loop momentum cutoff, the two-loop ,$\beta$-function of the $N=1$ supersymmetric electrodynamics is calculated.
Show AbstractVacuum polarization with the contribution of quarks that interact with the interfering electromagnetic and non-Abelian gauge background fields in an $SU(3)\times U(1)$ model of QFT at finite temperature is considered. In the one-loop approximation, the expression for the effective potential describing interference of the external electromagnetic $\vec{E}, \vec{H}$ and the vacuum chromomagnetic $\vec{B}$ fields is obtained. The finite temperature effect on the contribution of interfering fields to the vacuum energy of the model is analyzed.
Show AbstractThe fractions $\Phi_Z$ of the nuclei in beams of fast ions with atomic numbers $Z=3\div36$ and energies $2\div200$ MeV/nucleon that have passed through a solid carbon and a gaseous nitrogen target have been determined. It is found that, at ion energies in excess of $0.15 Z^{1.8}$ MeV/nucleon, the equilibrium thicknesses $t_Z$ of the nitrogen and carbon targets are practically the same.
Show AbstractA parametric model of expected uncertainty in detecting weak signals by means of gravitational-wave antennas under two-mode operation is considered.
Show AbstractA special type of quantum information-compatible information, that is an. analog of the Shannon classical mutual information for quantum systems, is considered. For an actual physical system formed by a pair of two-level atoms interacting in accordance with the Dicke model, the relationship between compatible information and the parameters and initial state of the system is analyzed.
Show AbstractBy photoreflection spectroscopy, the epitaxial GaAs/Al$_x$Ga$_{1-x}$As heterostructures with quantum well widths of 10, 20, and 30 nm were studied. At room temperature, in the photoreflection spectra, alongside with lines in the regions of the GaAs (1.4 eV) and Al$_x$Ga$_{1-x}$As (1.74 eV) fundamental transitions, spectral features related to dimensional quantization in the well and to the splitting of the valence band into subbands of heavy and light holes were observed. The experimental level energies agreed well with those calculated under the envelope wave function model.
Show AbstractThe dielectric properties of Langmuir-Blodgett films of 20 and 30 monolayers (100-150 A thick) of a 70/30 polyvinylidene fluoride-trifluoroethylene copolymer were studied. Several peculiarities in the behavior of $ε',ε''$ nontypical of bulk samples of the same composition were observed. Jn particular, in the surface phase transition region at 20$^о$C, as the frequency increased from 80 Hz to 20 kHz, a pronounced shift of the $ε'$ maximum to the lower temperatures was observed. In the frequency dependence of $ε''$, a smeared maximum at 300-500 Hz likely to be caused by macroformations was observed.
Show AbstractBy constructing an effective Hamiltonian allowing for the long-range forces due to the depolarization field, the phase transition and domain structure formation processes in KDP-type crystals are studied. Based on the model developed, the conclusion is drawn that the domain profile suffers sagging at the domain center, and the incommensurate phase formation mechanism requiring no refinement of the microscopic model is suggested.
Show AbstractThe spin dynamics of a neutral particle with anomalous magnetic moment in an arbitrary electromagnetic field in the quasiclassical approximation is studied. Fields for which the solution to the Bargmann-Michel-Telegdi equation can be represented in a finite form are found.
Show AbstractThe pulsed racetrack microtron-an electron accelerator of new generation built at the Research Institute of Nuclear Physics, Moscow State University, is briefly described. The unit's main characteristics and components are considered, and possible applications specified.
Show AbstractOn the basis of its formation model, additional energy stored in the Pacific tropical basin has been estimated. The maximum number of tropical cyclones that can form due to this additional El Ni$\tilde{n}$o energy supplied to the atmosphere has been calculated.
Show AbstractThe investigation results on vertical and horizontal structures of turbulence generated by a vibrating lattice both in clear water and a suspension are presented. Near the lattice, a horizontal periodic structure of the liquid vibrations of a jet nature has been revealed. With distance from the vibrating lattice, the liquid's reciprocating motion gets damped, and, other things being equal, the velocity (dispersion) values in the suspension are lower than in clear water. This is attributed to the perturbation energy absorption by solid particles and their precipitation rate decrease.
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