Search for dissertations about: "eigenvalue problems"

Showing result 16 - 20 of 50 swedish dissertations containing the words eigenvalue problems.

  2. 16. Critical point theory with applications to semilinear problems without compactness

    Author : Sara Maad; Jacqueline Fleckinger; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; MATEMATIK; MATHEMATICS; MATEMATIK; Mathematics; Matematik;

    Abstract : The thesis consists of four papers which all regard the study of critical point theory and its applications to boundary value problems of semilinear elliptic equations. More specifically, let Ω be a domain, and consider a boundary value problem of the form -L u + u = f(x,u) in Ω, and with the boundary condition u=0. READ MORE

  4. 17. Model Order Reduction with Rational Krylov Methods

    Author : K. Henrik A. Olsson; Axel Ruhe; Volker Mehrmann; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Model order reduction; dual rational Arnoldi; rational Krylov; moment matching; eigenvalue computation; stability analysis; heat exchanger model; Numerical analysis; Numerisk analys;

    Abstract : Rational Krylov methods for model order reduction are studied. A dual rational Arnoldi method for model order reduction and a rational Krylov method for model order reduction and eigenvalue computation have been implemented. It is shown how to deflate redundant or unwanted vectors and how to obtain moment matching. READ MORE

  5. 18. 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

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

    Author : Sven-Erik Ekström; Maya Neytcheva; Stefano Serra-Capizzano; Carlo Garoni; Lothar Reichel; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  7. 20. Some numerical and analytical methods for equations of wave propagation and kinetic theory

    Author : Eva Mossberg; Alexander Bobylev; Giovanni Russo; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; wave propagation; finite difference metods high order methods; Landau-Fokker-Planck equation; Monte-Carlo simulations; Boltzmann equation; hard sphere model; eigenvalue problem; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

    Abstract : This thesis consists of two different parts, related to two different fields in mathematical physics: wave propagation and kinetic theory of gases. Various mathematical and computational problems for equations from these areas are treated. READ MORE