Sökning: "Annemarie Luger"
Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Annemarie Luger.
1. Generalized Titchmarsh-Weyl functions and super singular perturbations
Sammanfattning : In this thesis we study certain singular Sturm-Liouville differential expressions from an operator theoretic point of view.In particular we are interested in expressions that involve strongly singular potentials as introduced by Gesztesy and Zinchenko. LÄS MER
2. Realizations of meromorphic functions of bounded type
Sammanfattning : A realization of a locally analytic function is basically a way of expressing the function in terms of the resolvent of a self-adjoint operator. In the classical Hilbert space setting realizations correspond in an essentially one-to-one way to Herglotz-Nevanlinna functions. LÄS MER
3. Integral representations of Herglotz-Nevanlinna functions
Sammanfattning : In this thesis, we study integral representations of Herglotz-Nevanlinna functions, that is to say holomorphic functions defined on a product of several copies of the complex upper half-plane having non-negative imaginary part. The manuscript is divided into three parts, beginning with a general introduction followed by two papers. LÄS MER
4. On Herglotz-Nevanlinna functions in several variables
Sammanfattning : In this thesis, we investigate different aspects of the class of Herglotz-Nevanlinna functions in several variables. These are holomorphic functions on the poly-upper half-plane having non-negative imaginary part. Our results are presented in the four research articles A1 - A4, which are included in this thesis. LÄS MER
5. On Supersingular Perturbations
Sammanfattning : This thesis consists of four papers and deals with supersingular rank one perturbations of self-adjoint operators and their models in Hilbert or Pontryagin spaces. Here, the term supersingular describes perturbation elements that are outside the underlying space but still obey a certain regularity conditions. LÄS MER
