R e g u l a r p a p e r s

Theoretical and mathematical physics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 1

Static scalar and electromagnetic test fields in а de Sitter space are studied. It is possiЫe to find solutions to equations for static conformally invariant fields without separation of variables. The complex vector potential is calculated bу using Debye potentials. From an expression for the time component of the vector potential the contribution made bу electromagnetic self-action to the force is estimated; the force of self-action is found to Ье equal to zero, with the electromagnetic contribution merely renormalizing the particle mass.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 8

Weakly nonlinear waves are studied on the surface of а shallow liquid with flotation. In terms of Lagrangian approximations, it is shown that the waves can Ье described bу the Korteweg-de Vries equation.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 13

Nondisturbing measurements with the purpose of detecting an action experienced bу the test body are different from what is required where one wants to measure the observaЫes of а free body. For detection, it is sufficient that the observed body-sensor system remain undisturbed during the measurement, but the value measured does not need to coincide with the value of the observable in а free body. The study demonstrates the impossibility of controlling, i.e. registering continuously with an arbitrarily small error, the velocity, the energy, and the components of а complex amplitude.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 17

The probability is calculated of generation of an electron-positron pair bу the field of а Coulomb center in а superstrong magnetic field. An equation is which defines implicitly the charge of а heavy nucleus at which а restructuring of the vacuum of electrons and positrons is initiated in Coulomb and superstrong magnetic fields (the critical charge). А function is constructed to characterize the space distribution of the electron charge in the new (charged) vacuum.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 22

The construction of quantum mechanics in the neighborhood of а blасk hole is studied. The principles of formalism offered in the paper are connected with symmetry properties of space-time and electromagnetic fields. The applicability limits of single-particle quantum mechanics in Einstein-Maxwell fields are inyestigated.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 29

Based on the rnethod of wave packets, а differential equation is derived for estirnating the state arnplitude $C_{L,R}$ of Dirac neutrinos with fixed helicity and electrornagnetic dipole moments $(μ_ν, d_ν)$ in an arbitrary electromagnetic field (Е, Н). Transitions vL↔vR are studied. It is demonstrated that for neutrinos from а supernova and neutron stars intensive transitions $ν_L →ν_R$ can take place at $(μ_ν, d_ν ~10^{- 11}, μ_8)$ for neutrinos from quasars such transitions can becorne significant already at $μ_ν, d_ν ~10^{- 17}, - 10^-18 μ_8$, where = ећ/2m_8с is Bohr's magneton.

Show AbstractAtomic and nuclear physics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 34

Estimates of magnetic moments of baryons of $1/2^+$ octet are analyzed in the framework of Borel rules of sums of QCD combined with а hypothesis of quark-biquark structure of baryons. For the contribution of а biquark an expression is derived: $-4e_q(1+δ_qq^8)eћ/(2cM_8),eh/(2cM8), where $δ_qq^8$ is а small correction calculated from QCD.

Show AbstractRadiophysics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 39

With а special reference to electrons captured bу а longitudinal wave and а straight electron bearn in а constant rnagnetic field it is dernonstrated that in conditions of anornalous Doppler effect incrernents of vibration can develop which are proportional to the resonance value of the electron distribution function rather than to the derivative of this function with respect to velocities sirnilar to direct and inverse darnping of Landau waves.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 44

The possibility is studied of spectral filtration of an image in the range of electromagnetic radiation wavelengths λ = 2.0-4.О μm bу an acoustooptical filter based on а paratellurite crystal. The basic filter parameters are calculated; the variation of the transverse shift angle and longitudinal shift of а diffracted image are estimated as а function of the radiation wave.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 49

Conservative difference schemes are used to study the generation of а powerful SHF radiation in waveguide systems bу relativistic electron beams whose currents are greater than the maximum vacuum current. The nonstationary nature of these phenomena is noted. SHF devices of this type are а promising concept for advances in the area of high powers.

Show AbstractOptics and spectroscopy

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 53

The superoperator technique of mathematical description of relaxing systems is briefly presented in terms of the theory of random processss, which is especially effective for studies of the relaxation properties of nonlinear and non-Markovian systems of nonlinear optics based on dynamic microscopic models.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 58

А phenomenological theory of self-action of elliptically polarized light in crystals of highest and medium categories is constructed. А new scheme of polarization spectroscopy is suggested which allows - independent of crystal symmetry - separation of the contributions of the various mechanisms of nonlinear optical rotation and deformation of the polarization ellipse, and provides twice as much information on сubiс nonlinearity and its spatial dispersion as the systems based on linearly polarized waves.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 64

With special reference to а classical model of а gas medium, polarization properties of а coherent anti-Stokes light scattering are derived which were described in an earlier work bу а cumbersome quantum calculation. The results of classical and quantum calculations coincide completely.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 67

The applicability is demonstrated of laser Doppler spectroscopy for determination of blооd flow velocity profiles in а glass capillary with the inner diameter of 100-400m. Experimental flow velocity profiles are described for water, blооd plasma, and diluted blооd with а hematocrit index Н ≤ 1%. Problems introduced bу multiple scattering in blооd at Н ≥ l-2% are discussed.

Show AbstractSolid state physics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 72

Isobaric $\gamma{i}^P$ and isothermal $\gamma{i}^T$ microscopic Gruneisen constants of quartz, diamond, silicon, and germanium crystals are calculated. It is shown that, from а comparison of $\gamma{i}^P$ and $\gamma_i{}^T$, the contributions bу phonon- phonon interactions and thermal expansion of а crystal to the temperature shift of the frequency of phonons can bе separated.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 78

Low-energy electron radiation is shown to bе сараblе of modifying substantially the fluctuation relief of the $Si—SiO_2$ interface and increasing the density of "fluctuational" surface electron states of the interface.

Show AbstractAstronomy

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 82

Ву the method of "incomplete integrals" а partial solution is constructed for the classical problem of two fixed centers, which describes parabolic motions. Ву inversion of quadratures in elliptic Jacobi functions, analytic expressions are obtained that are suitable for representing the motion of а star in the sphere of action of the nucleus of а spherical stellar cluster with adjustment for the perturbation bу the galactic nucleus.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 87

As relict radiation passes through the gravity field of galaxies its statistics is modified. The statistics of bursts of а random field от after passing near а galaxy is changed, so that, starting from а certain critical level, an exponential distribution is observed. This change of fluctuations от is equivalent to formation of а new generation of radio sources. The astrophysical properties of such sources are examined.

Show AbstractB r i e f r e p o r t s

Theoretical and mathematical physics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 93

The existence of zero fermionic mode in systems with Yukawian coupling is shown to make possible а specific formation mechanism of an nergy gap due to dynamic supersymmetry: there is а mixing of fermions and bosons as а result of exhhange of fermionic number during interaction with the zero mode.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 96

А formulation is offered of theory of time-angle distribution of the radiation of а system of relativistic particles that takes into account the probability distribution of shifts of particle trajectories in а bunch.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 100

The possibility is studied of reconstructing an optical spectral radiation from the energy of photoelectrons bу а reduct±on method. With this method, it is possible to eliminate the monochromator from the scheme.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 104

А new solution is offered of the one- dimensional Klein- Gordon equation with Coulomb gravity potential; it has а nonrelativistic limit which coincides with the nonrelativistic physically ассерtаЫе solution for а one-dimensional hydrogen atom.

Show AbstractOptics and spectroscopy

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 107

In temperature region of 210-180 К, the quantum yield of rhodmaine 6G fluorescence in ethanol is reduced. PossiЬle causes of this effect are suggested.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 110

In а comparison of variations of the magnetic susceptibility of CaS-Eu and the EPR signal of $Eu^{2+}$ with thermally stimulated luminescence peaks, the polarities of the released carriers are determined. It is shown that during excitation in the $Eu^{2+}$ band both electron and hole capture centers become populated.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 114

Experiments are described where phase-locked loops are used to filter two separate frequencies from vibration spectra of multifrequency spin generation. The difference frequency is then measured with а high accuracy.

Show AbstractAcoustics and molecular physics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 117

The study demonstrates that from effective elastic moduli of second, third, and fourth order, the compressive and tensile strengths of brittle materials can bе estimated.

Show AbstractMoscow University Physics Bulletin 1989. ** 1989**. N 2. P. 120

An application of the impedance method of acoustic sound velocity and absorption measurements in thin films is studied. А method is proposed for measuring sound velocity and absorptance in case of reflection from one or two thin layers.

Show AbstractSolid state physics

Moscow University Physics Bulletin 1989. ** 1989**. N 2. P. 123

Energy spectra of electrons emitted bу thin tungsten and molybdenum single crystals on the side opposite to the face bombarded bу argon ions have been measured.

Show Abstract