Sökning: "eigenvalues"

Visar resultat 21 - 25 av 110 avhandlingar innehållade ordet eigenvalues.

  1. 21. Trace Formulae for Fourth Order Differential Operators and their Applications

    Författare :Jörgen Östensson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : 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. LÄS MER

  3. 22. Quiescent regimes in cosmology

    Författare :Hans Oude Groeniger; Hans Ringström; Mattias Dahl; Todd Oliynyk; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quiescence; Bianchi spacetimes; big bang formation; G2 cosmology; Wainwright-Hsu variables; Klein-Gordon equation; Matematik; Mathematics;

    Sammanfattning : This thesis is about cosmological solutions to Einstein’s equations of general relativity, in particular spacetimes whose mean curvature diverges. Moreover, we consider anisotropic spacetimes with big bang singularities. In this setting the singularity is expected to generically be oscillatory if no matter is present. LÄS MER

  4. 23. Spectral properties of elliptic operators in singular settings and applications

    Författare :Medet Nursultanov; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The present thesis is focused on the investigation of the spectral properties of the linear elliptic operators in the presence of singularities. It is divided into three chapters. In the first chapter, we consider geometric singularities. LÄS MER

  5. 24. The Dirac Operator; From Numerics to the Theory of G-convergence

    Författare :Hasan Almanasreh; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Dirac operator; spuriousity; cubic Hermitian; stability parameter; G-convergence; ¡-convergence; spectral measure; quadratic form; stability parameter;

    Sammanfattning : We consider two main issues concerning the Dirac operator, the first is widely known as the appearance of spurious eigenvalues within the spectrum. The second is the study of the asymptotic behavior of the eigenvalues for a family of Dirac operators with oscillatory potential added to the Coulomb-Dirac Hamiltonian. LÄS MER

  7. 25. Parallel Algorithms and Library Software for the Generalized Eigenvalue Problem on Distributed Memory Computer Systems

    Författare :Björn Adlerborn; Bo Kågström; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; computer and systems sciences; data- och systemvetenskap;

    Sammanfattning : We present and discuss algorithms and library software for solving the generalized non-symmetric eigenvalue problem (GNEP) on high performance computing (HPC) platforms with distributed memory. Such problems occur frequently in computational science and engineering, and our contributions make it possible to solve GNEPs fast and accurate in parallel using state-of-the-art HPC systems. LÄS MER