Search for dissertations about: "Per Alexandersson"

Found 5 swedish dissertations containing the words Per Alexandersson.

  2. 1. Combinatorial Methods in Complex Analysis

    Author : Per Alexandersson; Boris Shapiro; Alexandre Eremenko; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; combinatorics; Schrödinger equation; Toeplitz matrix; sums of squares; Schur polynomials; Mathematics; matematik;

    Abstract : The theme of this thesis is combinatorics, complex analysis and algebraic geometry. The thesis consists of six articles divided into four parts.Part A: Spectral properties of the Schrödinger equationThis part consists of Papers I-II, where we study a univariate Schrödinger equation with a complex polynomial potential. READ MORE

  4. 2. On eigenvalues of the Schrödinger operator with a complex-valued polynomial potential

    Author : Per Alexandersson; Boris Shapiro; Ilpo Laine; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; schroedinger; even spectral determinant polynomial potential eigenvalue; Mathematical analysis; Analys; Mathematics; matematik;

    Abstract : In this thesis, we generalize a recent result of A. Eremenko and A. Gabrielov on irreducibility of the spectral discriminant for the Schroedinger equation with quartic potentials. READ MORE

  5. 3. Linear differential operators and their Hutchinson invariant sets

    Author : Nils Hemmingsson; Boris Shapiro; Per Alexandersson; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; matematik; Mathematics;

    Abstract : In this licentiate thesis we consider problems related to what we call Hutchinson invariance, which is a form of invariance for sets in the complex plane or the Riemann sphere with respect to the action of special differential operators.In the introductory chapter, we provide a background on Hutchinson invariance, explain how it relates to other problems in dynamical systems and why it is an interesting subject of study. READ MORE

  6. 4. Incubating Businesses

    Author : Anna Alexandersson; Chris Steyaert; Linnéuniversitetet; []
    Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Business incubation; entrepreneurship; organizational entrepreneurship; Ledarskap; entreprenörskap och organisation; Ledarskap; entreprenörskap och organisation; Business administration; Företagsekonomi;

    Abstract : The efficiency of business incubators is disputed, but they have attracted significant attention from policy-makers and are a part of economic policies worldwide. To ensure their efficiency, it has been suggested that more involvement in the ventures by the incubator management would be beneficial. READ MORE

  7. 5. Studies on colonoscopy and inflammatory conditions of the colon

    Author : Bjarki Alexandersson; Karolinska Institutet; Karolinska Institutet; []
    Keywords : ;

    Abstract : Background: Colonoscopy is a key investigative tool in inflammatory bowel disease and diverticular disease, but elements of the pathogenesis, symptomatology and safety of procedures in these two conditions remain unknown. The best surveillance method for colorectal cancer in inflammatory bowel disease (IBD) is debated. READ MORE