244 research outputs found

    Many closed K-magnetic geodesics on S^2

    Get PDF
    2noIn this paper we adopt an alternative, analytical approach to Arnol’d problem about the existence of closed and embedded K-magnetic geodesics in the round 2-sphere ^2, where :^2→ℝ is a smooth scalar function. In particular, we use Lyapunov-Schmidt finite-dimensional reduction coupled with a local variational formulation in order to get some existence and multiplicity results bypassing the use of symplectic geometric tools such as the celebrated Viterbo’s theorem and Bottkoll results.openopenopenMusina, Roberta; Zuddas, FabioMusina, Roberta; Zuddas, Fabi

    Bubbles with constant mean curvature, and almost constant mean curvature, in the hyperbolic space

    Get PDF
    Given a constant k>1k>1, let ZZ be the family of round spheres of radius extrmartanh(k1) extrm{artanh}(k^{-1}) in the hyperbolic space mathbbH3mathbb{H}^3, so that any sphere in ZZ has mean curvature kk. We prove a crucial nondegeneracy result involving the manifold ZZ. As an application, we provide sufficient conditions on a prescribed function phiphi on mathbbH3mathbb{H}^3, which ensure the existence of a calC1{cal C}^1-curve, parametrized by arepsilonapprox0arepsilonapprox 0, of embedded spheres in mathbbH3mathbb{H}^3 having mean curvature k+arepsilonphik +arepsilonphi at each point

    Fractional operators as traces of operator-valued curves

    Get PDF
    We relate non integer powers Ls{\mathcal L}^{s}, s>0s>0 of a given (unbounded) positive self-adjoint operator L\mathcal L in a real separable Hilbert space H\mathcal H with a certain differential operator of order 2s2\lceil{s}\rceil, acting on even curves RH\mathbb R\to \mathcal H. This extends the results by Caffarelli--Silvestre and Stinga--Torrea regarding the characterization of fractional powers of differential operators via an extension problem

    Heterogeneity of filtration in the upper part of the geologic cross-section in Vostochno-Zakamsky oil region of the Republic of Tatarstan

    Get PDF
    In Tatarstan continuous oil mining has caused large scale pollution of underground water in upper part of the geological section. As a result, there is the increasing problem of quality drinking water supply in many settlements. In this connection, we examined the nature and major filtration heterogeneity Nizhnekazanskogo aquifer. This is the most productive part of the section on underground water for drinking water.Comprehensive review of a variety of data allowed us to establish five main factors: geological, structural, hypsometric, geomorphological and facial. Their combination forms an increased filtration background of rocks. First of all, results allow to choose optimal position of the new water wells and rational planning and exploration work for the underground drinking water

    The role of english langauge at the Ural state medical university.

    Get PDF
    This study considers efficiency of the English language education in the Ural state medical university. The students survey showed the necessity of additional English classes to increase the level of vocational training and communication with colleagues

    Weighted Sobolev spaces of radially symmetric functions

    Full text link
    We prove dilation invariant inequalities involving radial functions, poliharmonic operators and weights that are powers of the distance from the origin. Then we discuss the existence of extremals and in some cases we compute the best constants.Comment: 38 page

    Integration of a specialist into the international space: linguistic training and cross cultural interaction

    Get PDF
    The article considers the possibilities of international internships for medical students and doctors. The problems of insufficient linguistic training of health care manpower for representing Russian Federation at the international level are discussed. Ways to work out these issues are suggested
    corecore