Sökning: "SPECTRAL ASYMPTOTICS"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden SPECTRAL ASYMPTOTICS.

  1. 1. Asymptotic and universal spectral estimates with applications in many-body quantum mechanics and spectral shape optimization

    Författare :Simon Larson; Ari Laptev; Stefan Steinerberger; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spectral theory; shape optimization; semiclassical asymptotics; spectral inequalities; quantum mechanics; Mathematics; Matematik;

    Sammanfattning : This thesis consists of eight papers primarily concerned with the quantitative study of the spectrum of certain differential operators. The majority of the results split into two categories. LÄS MER

  3. 2. Spectral Asymptotics in Porous Media

    Författare :Hermann Douanla Yonta; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Homogenization; reiterated homogenization; perforated domains; multiscale perforation; eigenvalue problems; ergodic algebra; algebra with mean value; Gelfand transformation; two-scale convergence; Sigma-convergence; Gelfand transformation;

    Sammanfattning : .... LÄS MER

  4. 3. Titchmarsh-Weyl M-function asymptotics and some results in the inverse spectral theory for vector-valued Sturm-Liouville equations and a certain higher order ordinary differential equation

    Författare :Erik Andersson; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Functions; differential equations; Funktioner; differentialekvationer; Paley-Wiener.; The generalized Fourier transform; A certain higher order ordinary differential equation; Borg-Marchenko theorems; Vector-valued Sturm-Liouville equations; Inverse spectral theory; Titchmarsh-Weyl M-function asymptotics; Asymptotics of solutions; Spectral measure;

    Sammanfattning : This discourse is constituted by two separate reprots, where the first one offers an elementary deduction of the leading order term asymptotics for the Titchmarsh-Weyl M-function corresponding to a vector-valued Sturm-Liouville equation of the form -(PU')'+QU=zu, xin[0,b), with P^{-1},W,Q being hermitean with locally integrable entries; and under some additional conditions on P^{-1} and W. In the special case of P=W=I, we give some further asymptotic results for the same M-function. LÄS MER

  5. 4. 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

  7. 5. 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