Search for dissertations about: "eigenvalues and eigenfunctions"

Showing result 1 - 5 of 6 swedish dissertations containing the words eigenvalues and eigenfunctions.

  2. 1. Heterogeneous Materials - Diffusion, Laplace Spectrum, and Nuclear Magnetic Resonance

    Author : Matias Nordin; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; eigenfunctions; eigenvalues; propagator; diffusion; Laplace operator; Nuclear Magnetic Resonance;

    Abstract : In this thesis diffusion in heterogeneous materials is studied using spectral analysisof the Laplace operator. Relations to the effective diffusion constant and therelaxation rate of the time-dependent diffusion coefficient for porous systems arederived from the Laplace operator’s spectrum. READ MORE

  4. 2. Some new results concerning general weighted regular Sturm-Liouville problems

    Author : Mervis Kikonko; Lars-Erik Persson; Peter Wall; Angelo B. Mingarelli; Alexey Karapetyants; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Partial differential equations; Sturm-Liouville problem; Right-definite; left-definite; non-definite; indefinite; Dirichlet problem; spectrum; eigenvalues; non-real eigenvalues; Richardson number; Richardson index; turning point; Mathematics; Matematik;

    Abstract : In this PhD thesis we study some weighted regular Sturm-Liouville problems in which the weight function takes on both positive and negative signs in an appropriate interval [a,b]. With such  problems there is the possible existence of non-real eigenvalues, unlike in the definite case (i.e. READ MORE

  5. 3. Trace Formulae for Fourth Order Differential Operators and their Applications

    Author : Jörgen Östensson; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Paper I. Trace Formulae and Spectral Properties of FourthOrder Differential Operators.We derive trace formulae forfourth order differential operators in dimension one anddiscuss their connection with sharp Lieb-Thirring inequalitiesfor the Riesz means of negative eigenvalues of order γ≥ 7/4. READ MORE

  6. 4. Spectral estimates for the magnetic Schrödinger operator and the Heisenberg Laplacian

    Author : Anders Hansson; Ari Laptev; B Malcolm Brown; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; spectral theory; Schrödinger operator; magnetic field; Aharonov-Bohm; Lieb-Thirring; diamagnetic inequality; Heisenberg group; Heisenberg Laplacian; hypoelliptic; spektralteori; Schrödingeroperator; magnetfält; Aharonov-Bohm; Lieb-Thirring; diamagnetisk olikhet; Heisenberggrupp; Heisenberg-Laplace-operator; hypoelliptisk; MATHEMATICS; MATEMATIK;

    Abstract : I denna avhandling, som omfattar fyra forskningsartiklar, betraktas två operatorer inom den matematiska fysiken. De båda tidigare artiklarna innehåller resultat för Schrödingeroperatorn med Aharonov-Bohm-magnetfält. READ MORE

  7. 5. On eigenvalues of the Schrödinger operator with a complex-valued polynomial potential

    Author : Per Alexandersson; Boris Shapiro; Ilpo Laine; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; schroedinger; even spectral determinant polynomial potential eigenvalue; Mathematical analysis; Analys; Mathematics; matematik;

    Abstract : In this thesis, we generalize a recent result of A. Eremenko and A. Gabrielov on irreducibility of the spectral discriminant for the Schroedinger equation with quartic potentials. READ MORE