Sökning: "Operators"

Visar resultat 1 - 5 av 825 avhandlingar innehållade ordet Operators.

  1. 1. Studies of some Operators of Harmonic Analysis in certain Function Spaces with Applications to PDEs

    Författare :Staffan Lundberg; Norway Narvik UiT The Arctic University of Norway Department of Computer Science and Computational Engineering Faculty of Science and Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Operators; Hardy Operators; Potential Operators; Singular Operators; Function Spaces; Morrey Spaces; H¨older Spaces; Partial Differential Equations; Inequalities; Hardy Type Inequalities; Weights; Applications; Matematik; Mathematics;

    Sammanfattning : The study in this PhD thesis aims at development of certain mathematical methods used in applications, in particular, in the study of regularity properties of solutions in various mathematical models described by Partial Differential Equations (PDEs). To this end, we study various operators of harmonic analysis in certain function spaces, since solutions to many PDEs may be expressed in terms of such operators. LÄS MER

  3. 2. Infinite dimensional holomorphy in the ring of formal power series : partial differential operators

    Författare :Henrik Petersson; Andrei Khrennikov; Sean Dineen; Växjö universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Infinite dimensional holomorphy; Formal power series; Fourier-Borel transform; Paley-Wiener theorem; Fischer decomposition; Fischer pair; Fock space; Cauchy-Problem; Kergin operator; PDE-preserving; Pseudo-differential operators.; MATHEMATICS; MATEMATIK;

    Sammanfattning : We study holomorphy in the ring of formal power series in an infinite number of variables. Thus we restrict our study to (infinite dimensional) holomorphy on sequence spaces and we show that we obtain a rich theory without requiring any topological structure on the domain space. We make a comprehensive PDO-study for the spaces under consideration. LÄS MER

  4. 3. Resolvent Estimates and Bounds on Eigenvalues for Schrödinger and Dirac Operators

    Författare :Alexandra Enblom; Vladimir Kozlov; Ari Laptev; David Krejcirik; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spectral theory; Schrödinger operators; polyharmonic operators; Dirac operators; non-self-adjoint perturbations; complex potential; estimation of eigenvalues; Carleman inequalities; Hardy inequalities;

    Sammanfattning : This thesis concerns the spectral theory of Schrödinger and Dirac operators. The main results relate to the problems of estimating perturbed eigenvalues. The thesis is based on four papers.The first paper focuses on the problem of localization of perturbed eigenvalues for multidimensional Schrödinger operators. LÄS MER

  5. 4. Schrödinger Operators in Waveguides

    Författare :Tomas Ekholm; Timo Weidl; Ari Laptev; Pavel Exner; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Schrödinger Operators; Hardy Inequalities; Mathematical physics; Matematisk fysik;

    Sammanfattning : In this thesis, which consists of four papers, we study the discrete spectrum of Schrödinger operators in waveguides. In these domains the quadratic form of the Dirichlet Laplacian operator does not satisfy any Hardy inequality. LÄS MER

  7. 5. Recursive descent parsing of user defined distfix operators

    Författare :Annika Aasa; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; distfix; operators; user defined syntax; recursive descent; ambiguity; grammars; parsing;

    Sammanfattning : .... LÄS MER