1,145 research outputs found

    Loop Variables for a Class of Conical Spacetimes

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    Loop variables are used to describe the presence of topological defects in spacetime. In particular we study the dependence of the holonomy transformation on angular momentum and torsion for a multi-chiral cone. We also compute the holonomies for multiple moving crossed cosmic strings and two plane topological defects-crossed by a cosmic string.Comment: 17 pages, LATE

    Influence of complex configurations on properties of pygmy dipole resonance in neutron-rich Ca isotopes

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    Starting from the quasiparticle random phase approximation based on the Skyrme interaction SLy5, we study the effects of phonon-phonon coupling~(PPC) on the low-energy electric dipole response in 4058^{40-58}Ca. Using the same set of parameters we describe available experimental data for 40,44,48^{40,44,48}Ca and give prediction for 5058^{50-58}Ca. The inclusion of the PPC results in the formation of low-energy 11^- states. There is an impact of the PPC effect on low-energy E1E1~strength of 40,44,48^{40,44,48}Ca. The PPC effect on the electric dipole polarizability is discussed. We predict a strong increase of the summed E1E1~strength below 10MeV, with increasing neutron number from 48^{48}Ca till 58^{58}Ca.Comment: 11 pages, 10 figure

    Structure of low-lying quadrupole states in nuclei near 132Sn

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    The properties of the low-lying 2^+ states in the even-even nuclei around 132Sn are studied within the quasiparticle random phase approximation. Starting from a Skyrme interaction in the particle-hole channel and a density-dependent zero-range interaction in the particle-particle channel, we use the finite rank separable approach in our investigation. It is found that the fourth 2^+ state in 132Te could be a good candidate for a mixed-symmetry state.Comment: 6 pages, 2 figures, proceedings of International Conference on Nuclear Structure and Related Topics (NSRT09), June 2009, JINR, Dubna, Russi

    Q-phonon description of low lying 1^- two-phonon states in spherical nuclei

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    The properties of 1^-_1 two-phonon states and the characteristics of E1 transition probabilities between low-lying collective states in spherical nuclei are analysed within the Q-phonon approach to the description of collective states. Several relations between observables are obtained. Microscopic calculations of the E1 0^+_1 -> 1^-_1 transition matrix elements are performed on the basis of the RPA. A satisfactory description of the experimental data is obtained.Comment: 16 pages, 2 figures, 9 table

    Dynamical-diffraction effects in parametric radiation

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    An analytic theory is developed for dynamical-diffraction effects in x-ray radiation from a relativistic electron traversing a thin single crystal. It is shown that such dynamical effects may be responsible for a glaring discrepancy between recent experimental data and the traditional theory of parametric x-ray radiationyesBelgorod State Universit

    Path space forms and surface holonomy

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    We develop parallel transport on path spaces from a differential geometric approach, whose integral version connects with the category theoretic approach. In the framework of 2-connections, our approach leads to further development of higher gauge theory, where end points of the path need not be fixed.Comment: 6 pages, 2 figures. Talk delivered by S. Chatterjee at XXVIII WGMP, 28th June-4th July, 2009. Bialowieza, Polan

    Higher education competitiveness : definition, assessment and ways of growth

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    The article is devoted to the search and the description of marketing reserves determining perspective competitiveness of higher educational establishments. The study refers to highly efficient institutions possessing the development potential and their own operational and marketing possibilities to comparative ways of growth. The research led to a conclusion that it is necessary to actualize the marketing competence of the Russian higher educational establishments based on the modernization of the educational activity through the development of the full-fledged training and production complexes providing the students with employment experience and real labor activity.peer-reviewe

    The analysis of defects propagation in navigating electronic devices

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    Defects in the form of microcracks in ??8?12 contacts of passive electronic components of navigating devices operating at different temperatures and pressure were analyzed. Research results have demonstrated the possibility of early prevention of potential accidents. Microscopic studies are systematized depending on various physical and chemical influences on devices. The mathematical model for defects definition in local points of contacts with an error of about 5 – 7.5 % has been applie

    The Poisson equations in the nonholonomic Suslov problem: Integrability, meromorphic and hypergeometric solutions

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    We consider the problem of integrability of the Poisson equations describing spatial motion of a rigid body in the classical nonholonomic Suslov problem. We obtain necessary conditions for their solutions to be meromorphic and show that under some further restrictions these conditions are also sufficient. The latter lead to a family of explicit meromorphic solutions, which correspond to rather special motions of the body in space. We also give explicit extra polynomial integrals in this case. In the more general case (but under one restriction), the Poisson equations are transformed into a generalized third order hypergeometric equation. A study of its monodromy group allows us also to calculate the "scattering" angle: the angle between the axes of limit permanent rotations of the body in space
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