Search for dissertations about: "Matematik naturvetenskapliga Fakulteten"

Showing result 21 - 25 of 46 swedish dissertations containing the words Matematik naturvetenskapliga Fakulteten.

  2. 21. On Steady Water Waves and Their Properties

    Author : Mats Ehrnström; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Particle trajectories; Water waves; Vorticity; Maximum principles; Elliptic equations;

    Abstract : Abstract: This thesis consists of four papers related to various aspects of steady water waves. Paper I: Deep-water waves with vorticity: symmetry and rotational behaviour. We show that for steady, periodic, and rotational gravity deep-water waves, a monotone surface profile between troughs and crests implies symmetry. READ MORE

  4. 22. Efficient Algorithms for Graph-Theoretic and Geometric Problems

    Author : Peter Floderus; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis studies several different algorithmic problems in graph theory and in geometry. The applications of the problems studied range from circuit design optimization to fast matrix multiplication. First, we study a graph-theoretical model of the so called ''firefighter problem''. READ MORE

  5. 23. Geometric Methods for some Nonlinear Wave Equations

    Author : Jonatan Lenells; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Natural science; Geodesic flow; Nonlinear wave equations; Geometric methods; Naturvetenskap;

    Abstract : A number of results related to the geometric interpretation of some dispersive nonlinear wave equations are presented. It is first described how some well-known shallow water equations arise geometrically as Euler equations for the geodesic flow on the Virasoro group endowed with certain right-invariant metrics. READ MORE

  6. 24. Kantor Triple Systems

    Author : Daniel Mondoc; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; gruppteori; fältteori; algebra; algebraic geometry; group theory; Talteori; field theory; Number Theory; Composition algebras; Jordan algebras; Kantor triple systems; Lie algebras; Jordan triple systems; algebraisk geometri;

    Abstract : The main purpose of this thesis is to study real exceptional Kantor triple systems. In the first paper we first prove the known results in both the real and complex classical cases of K-simple Kantor triple systems. In the real classical case our approach gives somewhat simpler formulas. READ MORE

  7. 25. On the existence of complex-valued harmonic morphisms

    Author : Jonas Nordström; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Harmonic morphisms; foliations; minimal submanifolds; Lie groups;

    Abstract : This thesis consists of 4 papers, their content is described below: Paper I. We present a new method for manufacturing complex-valued harmonic morphisms from a wide class of Riemannian Lie groups. This yields new solutions from an important family of homogeneous Hadamard manifolds. READ MORE