Sökning: "Laplace operator"

Visar resultat 16 - 20 av 29 avhandlingar innehållade orden Laplace operator.

  1. 16. Directional Decomposition in Anisotropic Heterogeneous Media for Acoustic and Electromagnetic Fields

    Författare :B. Lars G. Jonsson; KTH; []
    Nyckelord :directional wave-field decomposition; wave splitting; spectral reduction; aourstic anisotropy; electromagnetic anisotropy; generalized eigenvalue problem;

    Sammanfattning : Directional wave-field decomposition for heterogeneousanisotropic media with in-stantaneous response is establishedfor both the acoustic and the electromagnetic equations.We derive a sufficient condition for ellipticity of thesystem's matrix in the Laplace domain and show that theconstruction of the splitting matrix via a Dunford-Taylorintegral over the resolvent of the non-compact, non-normalsystem's matrix is well de ned. LÄS MER

  3. 17. Hardy and spectral inequalities for a class of partial differential operators

    Författare :Lior Alexandra Aermark; Ari Laptev; Thomas Hoffmann-Ostenhof; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; matematik;

    Sammanfattning : This thesis is devoted to the study of Hardy and spectral inequalities for the Heisenberg and the Grushin operators. It consists of five chapters. In chapter 1 we present basic notions and summarize the main results of the thesis. LÄS MER

  4. 18. Combinatorial and analytical problems for fractals and their graph approximations

    Författare :Konstantinos Tsougkas; Anders Karlsson; Anders Öberg; Ben Hambly; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fractal graphs; energy Laplacian; Kusuoka measure; Mathematics; Matematik;

    Sammanfattning : The recent field of analysis on fractals has been studied under a probabilistic and analytic point of view. In this present work, we will focus on the analytic part developed by Kigami. The fractals we will be studying are finitely ramified self-similar sets, with emphasis on the post-critically finite ones. LÄS MER

  5. 19. Studies in potential theory and function spaces

    Författare :Torbjörn Kolsrud; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : With an emphasis on capacities and fine topologies, some potential theoretic problems are treated in the framework of function spaces of Dirichlet and Sobolev type.We give a new characterization of the Sobolev spaces W0m,p(Ω). LÄS MER

  7. 20. Homogenization in Perforated Domains

    Författare :Martin Strömqvist; Henrik Shahgholian; Scott Armstrong; KTH; []
    Nyckelord :Mathematics; Matematik;

    Sammanfattning : Homogenization theory is the study of the asymptotic behaviour of solutionsto partial differential equations where high frequency oscillations occur.In the case of a perforated domain the oscillations are due to variations in thedomain of the equation. LÄS MER