Neutrino dispersion in external magnetic fields

We calculate the neutrino self-energy operator Sigma (p) in the presence of a magnetic field B. In particular, we consider the weak-field limit e B << m_\ell^2, where m_\ell is the charged-lepton mass corresponding to the neutrino flavor \nu_\ell, and we consider a "moderate field" m_\ell^2 << e B << m_W^2. Our results differ substantially from the previous literature. For a moderate field, we show that it is crucial to include the contributions from all Landau levels of the intermediate charged lepton, not just the ground-state. For the conditions of the early universe where the background medium consists of a charge-symmetric plasma, the pure B-field contribution to the neutrino dispersion relation is proportional to (e B)^2 and thus comparable to the contribution of the magnetized plasma.Comment: 9 pages, 1 figure, revtex. Version to appear in Phys. Rev. D (presentation improved, reference list revised, numerical error in Eq.(41) corrected, conclusions unchanged

1RXS J180834.7+101041 is a new cataclysmic variable with non-uniform disc

Results of photometric and spectroscopic investigations of the recently discovered disc cataclysmic variable star 1RXS J180834.7+101041 are presented. Emission spectra of the system show broad double peaked hydrogen and helium emission lines. Doppler maps for the hydrogen lines demonstrate strongly non-uniform emissivity distribution in the disc, similar to that found in IP Peg. It means that the system is a new cataclysmic variable with a spiral density wave in the disc. Masses of the components (M_WD = 0.8 +/- 0.22 M_sun and M_RD = 0.14 +/- 0.02 M_sun), and the orbit inclination (i = 78 +/- 1.5 deg) were estimated using the various well-known relations for cataclysmic variables.Comment: 4 pages, 3 figures, conference "European White Dwarf Workshop, 2010", Tuebingen, German

Spectral and localization properties of the Dirichlet wave guide with two concentric Neumann discs

Bound states of the Hamiltonian describing a quantum particle living on three dimensional straight strip of width $d$ are investigated. We impose the Neumann boundary condition on the two concentric windows of the radii $a$ and $b$ located on the opposite walls and the Dirichlet boundary condition on the remaining part of the boundary of the strip. We prove that such a system exhibits discrete eigenvalues below the essential spectrum for any $a,b>0$. When $a$ and $b$ tend to the infinity, the asymptotic of the eigenvalue is derived. A comparative analysis with the one-window case reveals that due to the additional possibility of the regulating energy spectrum the anticrossing structure builds up as a function of the inner radius with its sharpness increasing for the larger outer radius. Mathematical and physical interpretation of the obtained results is presented; namely, it is derived that the anticrossings are accompanied by the drastic changes of the wave function localization. Parallels are drawn to the other structures exhibiting similar phenomena; in particular, it is proved that, contrary to the two-dimensional geometry, at the critical Neumann radii true bound states exist.Comment: 25 pages, 7 figure

CPT and Lorentz violation effects in hydrogen-like atoms

Within the framework of Lorentz-violating extended electrodynamics, the Dirac equation for a bound electron in an external electromagnetic field is considered assuming the interaction with a CPT-odd axial vector background $b_\mu$. The quasi-relativistic Hamiltonian is obtained using a $1/c$-series expansion. Relativistic Dirac eigenstates in a spherically-symmetric potential are found accurate up to the second order in $b_0$. $b_0$-induced CPT-odd corrections to the electromagnetic dipole moment operators of a bound electron are calculated that contribute to the anapole moment of the atomic orbital and may cause a specific asymmetry of the angular distribution of the radiation of a hydrogen atom.Comment: 13 pages, 1 figure; (5.14) is corrected to conform to the normalization convention for Laguerre polynomials adopted at present; minor grammatical change

Communication of characteristics with sense of humour and characteristics of hardiness at students

The article presents data of theoretical bases of hardiness and sense of humour. The results of empiric research are presented on Ural State Pedagogical University students (n = 60 students, 17–22 years). A diagnostic tool was used: test of sense of humor H. Eysenk and H. Wilson, test of styles of humor M.Rod, test of hardiness of S. R. Maddi in adaptation of D. A. Leont’eva. Shows the relationship between characteristics of hardiness and abilities of sense of humour. The applied aspect of the investigated problem can be realized in development of the program of development of hardiness on facilities of development of sense of humour in group and in individual work.Изложены теоретические основания жизнестойкости и чувства юмора. Представлены результаты эмпирического исследования, выполненного на выборке студентов. Установлены связи между характеристиками жизнестойкости и чувством юмора

Legal regulation of mortgage lending: the experience of Russia and foreign countries

In this paper, authors carry out an analysis of regulation of legal relationships in the sphere of mortgage lending, based on studies of certain international legal acts, monographic publications and scientific publications. They analyze, in particular, the German mortgage lending system, elements of which are used in the development of the Russian mortgage system. The common features and peculiarities of mortgage lending in Germany and Russia are note