Search for dissertations about: "Weyl Calculus"

Found 3 swedish dissertations containing the words Weyl Calculus.

  1. 1. Continuity and Positivity Problems in Pseudo-differential Calculus

    Author : Joachim Toft; Matematik (naturvetenskapliga fakulteten); []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; funktionsanalys; fourieranalys; Serier; functional analysis; Fourier analysis; Series; Entropy.; Young s inequality; Twisted convolution; Schatten-von Neumann; Lower bounds; Weyl Calculus; Pseudo-differential Operqator; Continuity; Positivity;

    Abstract : The paper deals with various positivity and continuity questions arising in the Weyl calculus of pseudo-differential operators. Let W be a symplectic vector space. READ MORE

  2. 2. Homogenization of some problems in hydrodynamic lubrication involving rough boundaries

    Author : John Fabricius; Luleå tekniska universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Mathematics; partial differential equations; calculus of variations; homogenization theory; tribology; hydrodynamic lubrication; thin film flows; Reynolds equation; surface roughness; Weyl decomposition; Matematik; Matematik; Mathematics;

    Abstract : This thesis is devoted to the study of some homogenization problems with applications in lubrication theory. It consists of an introduction, five research papers (I–V) and a complementary appendix.Homogenization is a mathematical theory for studying differential equations with rapidly oscillating coefficients. READ MORE

  3. 3. Propagation of singularities for pseudo-differential operators and generalized Schrödinger propagators

    Author : Karoline Johansson; Joachim Toft; Anders Olofsson; Linnéuniversitetet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Banach spaces; Fourier; Generalized time-dependent Schrödinger equation; Micro-local; Modulation spaces; Non-tangential convergence; Pseudo-differential operators; Regularity; Wave-front sets; Banachrum; Fourier; Generaliserad tidsberoende Schrödinger ekvation; Icke-tangentiell konvergens; Mikrolokal; Modulationsrum; Pseudodifferentialoperatorer; Regularitet; Vågfrontsmängder; Mathematical analysis; Analys; Mathematics; Matematik;

    Abstract : In this thesis we discuss different types of regularity for distributions which appear in the theory of pseudo-differential operators and partial differential equations. Partial differential equations often appear in science and technology. READ MORE