Search for dissertations about: "Matematik naturvetenskapliga Fakulteten"

Showing result 16 - 20 of 46 swedish dissertations containing the words Matematik naturvetenskapliga Fakulteten.

2. 16. 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

   Author : Erik Andersson; Matematik (naturvetenskapliga fakulteten); []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 17. Complexes and Diffrerential Graded Modules

   Author : Dmitri Apassov; Matematik (naturvetenskapliga fakulteten); []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; algebraic geometry; field theory; Number Theory; fiber of a local homomorphism; DG dualizing module; homological dimensions; differential graded rings; almost finite module; Cohen-Macaulay rings; local homomorphism; Gorenstein rings; annihilator; complex of modules; algebra; group theory; Talteori; fältteori; algebraisk geometri; gruppteori;

   Abstract : The main topic of the thesis is the generalization of some traditional module-theoretic homological applications to complexes of modules and to differential graded modules over differential graded rings. We introduce three possible generalizations of the classical notion of annihilator of an R-module. READ MORE

5. 18. Hankel operators on the

   Author : Olivia Constantin; Matematik (naturvetenskapliga fakulteten); []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : licentiate theses in mathematical sciences.... READ MORE

6. 19. Some Resolvent Estimates in Harmonic Analysis

   Author : Anders Dahlner; Matematik (naturvetenskapliga fakulteten); []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; field theory; Number Theory; algebra; algebraic geometry; Talteori; group theory; Tauberian theorem. Quantitative inversion. Cesaro operator. Bishops property beta.; algebraisk geometri; fältteori; gruppteori;

   Abstract : This thesis contains three papers about three different estimates of resolvents in harmonic analysis. These papers are: Paper 1. ``A Wiener tauberian theorem for weighted convolution algebras of zonal functions on the automorphism group of the unit disc'' Paper 2. ``Uniform spectral radius and compact Gelfand transform'' Paper 3. READ MORE

7. 20. On Vertex Operator Algebras of Affine Type at Admissible Levels

   Author : Thomas Edlund; Matematik (naturvetenskapliga fakulteten); []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Vertex operator algebras; Kac-Moody algebras; Ore localization; Admissible levels; Singular vectors; Intertwining operators;

   Abstract : The main purpose of this thesis is the study of the structure and representation theory of simple vertex operator algebras (VOAs) of affine type at admissible levels. To do this, it is crucial to obtain knowledge of the singular vectors which generate the maximal submodules, with respect to which these VOAs appear as irreducible quotients, and therefore a substantial part of the text is devoted to this matter. READ MORE