Sökning: "asymptotics of eigenvalues"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden asymptotics of eigenvalues.

  1. 1. Matrix-Less Methods for Computing Eigenvalues of Large Structured Matrices

    Författare :Sven-Erik Ekström; Maya Neytcheva; Stefano Serra-Capizzano; Carlo Garoni; Lothar Reichel; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Toeplitz matrices; eigenvalues; eigenvalue asymptotics; polynomial interpolation; extrapolation; generating function and spectral symbol; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : When modeling natural phenomena with linear partial differential equations, the discretized system of equations is in general represented by a matrix. To solve or analyze these systems, we are often interested in the spectral behavior of these matrices. LÄS MER

  3. 2. Spectra of elliptic operators and applications

    Författare :Medet Nursultanov; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Helmholtz and Maxwell s equations; functional calculus; electromagnetic waveguide; acoustic waveguide; Sturm-Liouville operator; singular potential; asymptotics of eigenvalues; point interactions.;

    Sammanfattning : In this thesis we consider several problems related to elliptic equations. Namely, we investigate Helmholtz and Maxwell's equations in Paper I and Sturm-Liouville spectral problem in Papers II,III. In Paper I we study time-harmonic electromagnetic and acoustic waveguide, modeled by an in�nite cylinder with a non-smooth cross section. LÄS MER

  4. 3. Asymptotics of random matrices and matrix valued processes

    Författare :Stefan Israelsson; Kurt Johansson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Random matrices; singular interaction; spectral distribution; fluctuation limit; distribution valued processes; MATEMATIK; MATHEMATICS; MATEMATIK; matematisk statistik; Mathematical Statistics;

    Sammanfattning : This thesis contains three parts. In the first two papers we consider spectral properties of symmetric matrices with elements consisting of independent Ornstein Uhlenbeck processes. The eigenvalues behave as a particle system on the real line with singular interaction consisting of electrostatic repulsion and a linear restoring force. LÄS MER

  5. 4. Higher order differential operators on graphs

    Författare :Jacob Muller; Pavel Kurasov; Ram Band; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Almost periodic functions; differential operators on metric graphs; quantum graphs; estimation of eigenvalues;

    Sammanfattning : This thesis consists of two papers, enumerated by Roman numerals. The main focus is on the spectral theory of -Laplacians. Here, an -Laplacian, for integer , refers to a metric graph equipped with a differential operator whose differential expression is the -th derivative. LÄS MER

  7. 5. New Phenomena in the World of Peaked Solitons

    Författare :Marcus Kardell; Hans Lundmark; Stefan Rauch; Joakim Arnlind; Jonatan Lenells; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The aim of this work is to present new contributions to the theory of peaked solitons. The thesis consists of two papers,which are named “Newsolutionswith peakon creation in the Camassa–HolmandNovikov equations” and “Peakon-antipeakon solutions of the Novikov equation” respectively. LÄS MER