Search for dissertations about: "twisted convolutions"

Found 2 swedish dissertations containing the words twisted convolutions.

  2. 1. Continuity and compositions of operators with kernels in ultra-test function and ultra-distribution spaces

    Author : Yuanyuan Chen; Joachim Toft; Nenad Teofanov; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Composition; modulation spaces; positivity; pseudo-differential operators; Schatten-von Neumann operators; twisted convolutions; ultra-distributions; Matematik; Mathematics;

    Abstract : In this thesis we consider continuity and positivity properties of pseudo-differential operators in Gelfand-Shilov and Pilipović spaces, and their distribution spaces. We also investigate composition property of pseudo-differential operators with symbols in quasi-Banach modulation spaces. READ MORE

  4. 2. 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