Faculty of Physics
M.V.Lomonosov Moscow State University
Theoretical and mathematical physics

Evolution of the universe

Yu.M. Loskutov

Moscow University Physics Bulletin 2003. 58. N 6. P. 1

A scenario of the evolution of the Universe based on the notions of the densities of the substance energy and the gravitational field in the Minkowski space is proposed. It is shown that the Universe evolves (in proper time) cyclically between states with maximal and minimal substance densities; the total energy density always vanishes. The complete period of the evolution cycle is determined by the minimal substance density in the Universe. It is also shown that, in the Riemannian space (by an observer associated with this space), the observed evolution process is a sequence of alternating cycles of expansion and contraction. At the final stage of expansion, which lasts for several billion years, the obtained value of the deceleration parameter is negative, which agrees with the most recent astronomical data. The distance to the horizon is determined by the current substance density. In the suggested concept, an explanation for the cosmological red shift is suggested; the temperature regime of the Universe is studied. A theoretical explanation for the observed non-Faraday rotation of the polarization planes of the electromagnetic radiation of distant radio galaxies is offered.

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State space for quantum gravity

O.D. Timofeevskaya, O.A. Khrustalev, M.V. Chichikina

Moscow University Physics Bulletin 2003. 58. N 6. P. 13

The system's state space is constructed, and the explicit form of the field operator is obtained.

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A model for chiral symmetry breaking with a fermion guide gas

V.Ch. Zhukovskii, О.V. Tarasov

Moscow University Physics Bulletin 2003. 58. N 6. P. 19

A mechanism of chiral symmetry breaking (χSB) is proposed based on gauge field configurations (fermion guides) with finite density of fermion zero modes. These configurations are assumed to be random superpositions of gauge fields, where a fermion can propagate along a four-dimensional trajectory to arbitrary distances without reduction of its amplitude.

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Nonlinear evolution equation for mean occupation numbers in the Maslov probability space

A.V. Polyakov

Moscow University Physics Bulletin 2003. 58. N 6. P. 25

A system of particles with discrete set of states and constraints on the occupation numbers is studied. The classical Bernoulli scheme of trials and the quantum scheme corresponding to an arbitrary parastatistics are simultaneously considered. The number of particles is not fixed and has a Poisson distribution. It has been proved that, in both cases, the occupation numbers are independent random variables. In the case of the Markovian evolution of probabilities of states of separate particles, a nonlinear equation for the mean occupation numbers has been derived.

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Hybrid renormalization in the Wess-Zumino model

N.A. Kozlov

Moscow University Physics Bulletin 2003. 58. N 6. P. 32

Application of hybrid renormalization in the Wess—Zumino model has been considered. The Word identity has been proved. The general proof of the fact that the renormalization does not disturb the model symmetry has been performed.

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Atomic and nuclear physics

Effects of barion correlation and core deformation in hypernuclear three-, four-, and five-particle systems

A.G. Donchev, S.A. Kalachev, N.N. Kolesnikov, V.I. Tarasov

Moscow University Physics Bulletin 2003. 58. N 6. P. 37

Based on the direct three-, four-, and five-particle variation calculations of the 3$_\Lambda^3\rm H$, $_\Lambda^4\rm H$, $_\Lambda^4\rm H^*$, $_\Lambda^4\rm He$, $_\Lambda^4\rm He^*$ and $_\Lambda^5\rm He$ hypernuclei and also of the $^2\rm H$, $^3\rm H$, $^3\rm He$ and $^4\rm He$ nuclei, the effects of particle correlation as well as the core contractivity are investigated, and the conditions of applicability of the two-body ($\Lambda+{}$остов) model of hypernuclei are discussed.

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Study of azimuthal anisotropy in nuclear interactions of cosmic-ray particles

V.I. Galkin, A.K. Managadze, V.I. Osedlo, Т.M. Roganova, G. Shoziyoev

Moscow University Physics Bulletin 2003. 58. N 6. P. 43

The behavior of various anisotropy parameters as applied to the spatial distribution of cosmic-ray particles in gamma-hadronic families is considered. The sensitivity of the parameters chosen to the type of the parent particle of the given family is established. Using the RUNJOB experimental data, the spatial anisotropy and the alignment effect in cosmic-ray particle interactions at $E_0=10^{13}$-$10^{14}$eV are investigated.

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Coherent processing of the output signal of resonant gravitational-wave antennas against gaussian noise

A.V. Gusev, V.N. Rudenko

Moscow University Physics Bulletin 2003. 58. N 6. P. 49

Specific features of the processing of information obtained using solid-state resonant gravitational-wave antennas operating in the fast filtering mode when receiving wide-band gravitational pulses with unknown parameters against a background of additive Gaussian noise are considered.

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Optics and spectroscopy

Stability of nonplanar cavities of ring chip lasers

D.A. Aleshin, N.V. Kravtsov

Moscow University Physics Bulletin 2003. 58. N 6. P. 55

Stability of the nonplanar cavities of ring chip lasers is analyzed. Explicit expressions for the stability regions of such cavities are obtained.

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Acoustics and molecular physics

The electroacoustic effect in a strontium titanate single crystal under a structural phase transition

A.I. Korobov, Yu.A. Brazhkin, N.I. Odina

Moscow University Physics Bulletin 2003. 58. N 6. P. 61

Results of an experimental study of the special features of the electroacoustic effect in a strontium titanate single crystal in the region of a structural phase transition at $T\approx103$ К are presented. The propagation speed of longitudinal ultrasonic waves at a frequency 30 MHz as a function of the external electric field E is measured. As the temperature decreases and approaches $T\approx103$ K, the functional dependence of the sound speed on the electric field strength is observed to gradually change from quadratic to linear. The emergence of a linear contribution to the transition region is related to the defect-induced deviation of the lattice symmetry from the cubic one.

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Effect of the submicron metal film thickness on the efficiency of thermooptical generation of ultrasound in the substrate-film-liquid system

A.A. Karabutov, V.V. Kozhushko, I.M. Pelivanov, N.B. Podymova

Moscow University Physics Bulletin 2003. 58. N 6. P. 65

For a system where a metal film deposited on a quartz substrate contacts an immersion liquid, a direct optoacoustic problem is considered. The effect of film thickness on the efficiency of optoacoustic conversion is investigated. Chromium films of different thickness and two immersion liquids, acetone and ethanol, have been used in the experiment. The results of measurement and theoretical modeling suggest that a transfer function of optoacoustic conversion can be used to determine the thickness of submicron metal coatings and study their thermophysical parameters.

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Solid state physics

Discrete nature of nonmonotonic structural transformations in the Pd-Ta-H system in relaxation

V.M. Avdyukhina, A.A. Anishchenko, A.A. Katsnelson, A.I. Olemskoi, G.P. Revkevich

Moscow University Physics Bulletin 2003. 58. N 6. P. 71

By X-ray diffractometry a quasi-discrete relationship between the positions of peaks of diffraction reflection components and a diffraction angle on diffraction patterns of Pd—Та alloys in the state of relaxation after hydrogenation, which may be associated with a multivalley structure of a thermodynamic potential, was revealed. As a result, structural transformations in the course of degassing occur through transitions between long-lived metastable states corresponding to different minima of the multivalley structure.

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Interaction between electron and nuclear spin systems in magnetic field

V.L. Marchenko, A.M. Savchenko, В.I. Sadovnikov

Moscow University Physics Bulletin 2003. 58. N 6. P. 79

Interaction of an electron spin system with a nuclear spin system in easy-plane antiferromagnets in the case of a spin flip (spin-flip phase) is considered. This is important for studying thermodynamic and kinetic properties of nuclear systems. Equilibrium configurations of electron and nuclear magnetization are studied. The electron and nuclear spin systems are found to be related to elastic fields generated by crystal defects.

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Geophysics

Features of the increasing intensity of solar cosmic ray protons with energy over 1 mev on april 11-12, 1990 by the IMP-8 data

G.P. Lyubimov, V.I. Tulupov

Moscow University Physics Bulletin 2003. 58. N 6. P. 83

A short-term (up to 12 h) increase of the intensity of solar cosmic ray protons with energy $E>1$ MeV on April 11—12, 1990 according to the data recorded at the IMP-8 artificial Earth satellite is considered. The curve has two peaks. They are interpreted as ensembles of particles located in traps, the first peak corresponding to particles located in a heliospheric loop trap, and the second one, to particles in a trap behind the shock wave front.

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