The Thom Isomorphism in the “Twice” Equivariant K-Theory of C * -Bundles

We prove the Thom isomorphism theorem for the K-theory of bundles with fibers equal to a projective module over a C^*-algebra for the action of a compact Lie group both on this algebra and on the total space. Bibliography: 12 titles.     

Radiation-Transfer Modeling of the Cloud L1544 in the HCO+ and HC18O+ Emission Lines

We study the formation of HCO⁺ and HC¹⁸O⁺ emission lines in the cloud L1544. The radiation transfer is modeled numerically, and the line intensities for different impact parameters are calculated. It is shown that a decrease in the abundances of the studied molecules toward the object center is necessary for the formation of the observed line profile in the optically thin case. We consider various hydrodynamic models allowing for compression, turbulence, and different types of cloud rotation and find a model ensuring the best agreement with the observational data. Our numerical simulations are indicative of nonuniform rotation in L1544. Assuming that the object is spherically symmetric, we estimate the density and velocity of the medium within the framework of the selected model.     

Prototype of a Two-Wave Radiometric System of the Millimeter Wavelength Range for Remote Sensing of the Atmosphere and Features of Atmospheric Absorption at Kara-Dag According to Field Measurements

Radiophysics and Quantum Electronics - We discuss the results of the atmospheric absorption studies on the territory of the Kara-Dag radio astronomy station in Crimea in the millimeter-wavelength...     

Testing the correlations between ultrahigh-energy cosmic rays and BL Lac-type objects with HiRes stereoscopic data

Previously suggested correlations of BL Lac-type objects with the arrival directions of the ultrahigh-energy cosmic ray primaries are tested by making use of the HiRes stereoscopic data. The results of the study support the conclusion that BL Lacs may be cosmic ray sources and suggest the presence of a small (a few percent) fraction of neutral primaries at E > 10¹⁹ eV.     

Extraction of the neutron charge form factor G<Superscript>n</Superscript><Subscript>E</Subscript>(Q<Superscript>2</Superscript>) from the charge form factor of deuteron G<Superscript>d</Superscript><Subscript>C</Subscript>(Q<Superscript>2</Superscript>)

We extract the neutron charge form factor G ⁿ _E(Q ²) from the charge form factor of deuteron G ^d _C(Q ²) obtained from T ₂₀(Q ²) data at 0≤Q ²≤ 1.717 (GeV/c)². The extraction is based on the relativistic impulse approximation in the instant form of the relativistic Hamiltonian dynamics. Our results (12 new points) are compatible with existing values of the neutron charge form factor of other authors. We propose a fit for the whole set (36 points) taking into account the data for the slope of the form factor at Q ² = 0. Received: 26 July 2002 / Accepted: 18 September 2002 / Published online: 4 February 2003 RID="a" ID="a"e-mail: krutov@ssu.samara.ru RID="b" ID="b"e-mail: troitsky@theory.sinp.msu.ru Communicated by V.V. Anisovich     

Discrete groups actions and corresponding modules

We address the problem of interrelations between the properties of an action of a discrete group on a compact Hausdorff space and the algebraic and analytical properties of the module of all continuous functions over the algebra of invariant continuous functions . The present paper is a continuation of our joint paper with M. Frank and V. Manuilov. Here we prove some statements inverse to the ones obtained in that paper: we deduce properties of actions from properties of modules. In particular, it is proved that if for a uniformly continuous action the module is finitely generated projective over , then the cardinality of orbits of the action is finite and fixed. Sufficient conditions for existence of natural conditional expectations are obtained.

     

Semileptonic decays of Pseudoscalar mesons in the instant form of relativistic Hamiltonian dynamics

A formalism for describing semileptonic decays of pseudoscalar mesons is developed on the basis of the instant form of relativistic Hamiltonian dynamics. By way of example, this formalism is applied to the decay process $K^ - \to \pi ^0 + \mu ^ - + \bar \nu _\mu $ . Relevant calculations are performed with wave functions that correspond to various models of constituent-quark interactions in mesons. Free parameters that appear in these models are determined from a fit to the root-mean-square radii of the kaons and pions. The results of the calculations agree well with experimental data.     

Polarization Effects Due to Scattering of Microwave Radiation in ihe Summer Cloudy Atmosphere

We present the results of the spectral analysis of polarization of the thermal microwave emission from the summer cloudy atmosphere at 37 and 94 GHz. A significant polarization of the microwave emission from summer clouds is revealed, which is attributed to scattering of the thermal emission from the atmosphere by melted ice crystals in the melting layer. Based on a model of polarized radiation transfer in the mixed clouds containing melted ice crystals and supercooled water drops, we interpret the experimental data with allowance for all orders of scattering. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 48, No. 4, pp. 314–326, April 2005.