Parameters of galactic disks at optical and NIR wavelengths

We have analyzed the radial scales, central surface brightnesses, and colors of 404 disks of various types of galaxies. The central surface brightness mu0 and linear disk scale length h vary smoothly along the Hubble sequence of galaxies within a rather narrow interval. The disks of relatively early type galaxies display higher central surface brightnesses in K, higher central surface densities, smaller sizes (relative to the diameter of the galaxy), redder integrated and central colors. The color gradient normalized to the radius of the galaxy and the blue central surface brightness mu0_{0,i}(B) of the disk, are both independent of the galaxy type. The radial disk scales in different photometric bands differ less in early-type than in late-type galaxies. The ratio of linear disk scales measured in different photometric bands increases with the isophote ellipticity e of the disk (the inclination of the galaxy); however, the range of the ratio values for each e value exceeds the range of variations of scale lengths ratio over e. The disks in S0 galaxies have more homogeneous parameters than those in spiral galaxies. However, no sharp boundary in the properties of disks in lenticular, spiral, and irregular galaxies has been found; all parameters vary smoothly along the Hubble sequence. A correlation between the central disk surface brightness and the total luminosity of the galaxy is observed. We also consider the influence of dust on the photometric parameters of the disks. We show that the dust concentrated in dust lines towards the spiral arms and bars does not influence to the scale lengths ratio.Comment: 10 pages, 7 figures, 1 table. Published in Astronomical and Astrophysical Transaction

An implementation of the polynomial Lie algebra methods for solving a class of nonlinear models in quantum optics

We develop some calculation schemes to determine dynamics of a wide class of integrable quantum-optical models using their symmetry adapted reformulation in terms of polynomial Lie algebras $su_{pd}(2)$. These schemes, based on "diagonal" representations of model evolution operators (via diagonalizing Hamiltonians with the help of the $su_{pd}(2)$ defining relations), are implemented in the form adapted for numerical calculations. Their efficiency is demonstrated on the example of the second-harmonic-generation model.Comment: 9 pages, LATEX; submitted to Proceedings of XXIII Intternational Colloqium on Group Theoretical Methods in Physics (Dubna, July 31-August 5 2000

The universe evolution as a possible mechanism of formation of galaxies and their clusters

The Kepler problem is considered in a space with the Friedmann--Lemaitre--Robertson--Walker metrics of the expanding universe. The covariant differential of the Friedmann coordinates (X=a(t)x) is considered as a possible mechanism of the formation of galaxies and clusters of galaxies. The cosmic evolution leads to decreasing energy of particles, causing free particles to be captured in bound states. In this approach the evolution of the universe plays the role usually inscribed to Cold Dark Matter.Comment: 6 pages, 3 figure

Low frequency signals of large scale GW-interferometers

Application of the large scale gravitational wave interferometers for measurement of geophysical signals at very low frequencies is considered. Analysis is concentrated on the mechanism of penetration of quasistatic geophysical perturbation through the main interferometer output. It is shown that it has a parametrical nature resulted in slow variations of the optical transfer function of the interferometer. Geophysical modulation index is calculated for any harmonical component of the output spectrum, but mainly for a photon circulation frequency appeared in the case of stochastic illumination of modes neighbour to the central resonance. Value of the effect is estimated for different operational regimes of the device. For improvement of geophysical signal readout a modernization of the instrument with using of two component resonance optical pump is proposed and a correspondent calculation is carried out. Numerical estimations for different regimes of the setup are given together with discussion of possible application for measuring some weak gravitational effects.Comment: 29 pages, 1 figure, submitted to Classical and Quantum Gravit

Origin of Matter from Vacuum in Conformal Cosmology

We introduce the hypothesis that the matter content of the universe can be a product of the decay of primordial vector bosons. The effect of the intensive cosmological creation of these primordial vector $W, ~Z$ bosons from the vacuum is studied in the framework of General Relativity and the Standard Model where the relative standard of measurement identifying conformal quantities with the measurable ones is accepted. The relative standard leads to the conformal cosmology with the z-history of masses with the constant temperature, instead of the conventional z-history of the temperature with constant masses in inflationary cosmology. In conformal cosmology both the latest supernova data and primordial nucleosynthesis are compatible with a stiff equation of state associated with one of the possible states of the infrared gravitation field. The distribution function of the created bosons in the lowest order of perturbation theory exposes a cosmological singularity as a consequence of the theorem about the absence of the massless limit of massive vector fields in quantum theory. This singularity can be removed by taking into account the collision processes leading to a thermalization of the created particles. The cosmic microwave background (CMB) temperature T=(M_W^2H_0)^{1/3} ~ 2.7 K occurs as an integral of motion for the universe in the stiff state. We show that this temperature can be attained by the CMB radiation being the final product of the decay of primordial bosons. The effect of anomalous nonconservation of baryon number due to the polarization of the Dirac sea vacuum by these primordial bosons is considered.Comment: Latex file, 19 pages, 2 figures, Preprint JINR E2-2002-14

Cosmological Creation of Vector Bosons and Fermions

The cosmological creation of primordial vector bosons and fermions is described in the Standard Model of strong and electro-weak interactions given in a space-time with the relative standard of measurement of geometric intervals. Using the reparametrization - invariant perturbation theory and the holomorphic representation of quantized fields we derive equations for the Bogoliubov coefficients and distribution functions of created particles. The main result is the intensive cosmological creation of longitudinal Z and W bosons (due to their mass singularity) by the universe in the rigid state. We introduce the hypothesis that the decay of the primordially created vector bosons is the origin of the Cosmic Microwave Background radiation.Comment: 20 pages, 1 figure, discussion extended, typos correcte

Microwave induced nonlocal transport in two-dimensional electron system

We observe microwave induced nonlocal resistance in magnetotransport in single and bilayer electronic systems. The obtained results provide evidence for an edge state current stabilized by microwave irradiation due to nonlinear resonances. Our observation are closely related to microwave induced oscillations and zero resistance states in a two-dimensional (2D) electron system.Comment: 5 pages, 4 figure

On generation of the Bargmann-Moshinsky basis of SU(3) group

An efficient procedure of orthonormalisation of the Bargmann-Moshinsky (BM) basis is examined using analytical formulas of the overlap integrals of the BM basis. Calculations of components of the quadrupole operator between the both BM and the orthonormalised bases needed for construction of the nuclear models are tested. The proposed procedure is also implemented as the Fortran program.Comment: 13 pages, submitted to Journal of Physics: Conference Serie

Large anisotropic spin relaxation time of exciton bound to donor states in triple quantum wells

We have studied the spin dynamics of a dense two-dimensional electron gas confined in a GaAs/AlGaAs triple quantum well by using time-resolved Kerr rotation and resonant spin amplification. Strong anisotropy of the spin relaxation time up to a factor of 10 was found between the electron spins oriented in-plane and out-of-plane when the excitation energy is tuned to an exciton bound to neutral donor transition. We model this anisotropy using an internal magnetic field and the inhomogeneity of the electron g-factor. The data analysis allows us to determine the direction and magnitude of this internal field in the range of a few mT for our studied structure, which decreases with the sample temperature and optical power. The dependence of the anisotropic spin relaxation was directly measured as a function of several experimental parameters: excitation wavelength, sample temperature, pump-probe time delay, and pump power.Comment: 6 pages, 5 figure

Long-lived nanosecond spin coherence in high-mobility 2DEGs confined in double and triple quantum wells

We investigated the spin coherence of high-mobility two-dimensional electron gases confined in multilayer GaAs quantum wells. The dynamics of the spin polarization was optically studied using pump-probe techniques: time-resolved Kerr rotation and resonant spin amplification. For double and triple quantum wells doped beyond the metal-to-insulator transition, the spin-orbit interaction was tailored by the sample parameters of structural symmetry (Rashba constant), width and electron density (Dresselhaus linear and cubic constants) which allows us to attain long dephasing times in the nanoseconds range. The determination of the scales: transport scattering time, single-electron scattering time, electron-electron scattering time, and spin polarization decay time further supports the possibility of using n-doped multilayer systems for developing spintronic devices.Comment: 5 pages, 5 figure