Search for dissertations about: "Ralf Fröberg"

Showing result 6 - 8 of 8 swedish dissertations containing the words Ralf Fröberg.

  2. 6. Decomposition of modules over the Weyl algebra

    Author : Ibrahim Nonkane; Rikard Bögvad; Jan-Erik Björk; Ralf Fröberg; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; matematik; Mathematics;

    Abstract : The thesis consists of two papers that treat decomposition of modules over the Weyl algebra. In the first paper decomposition of holonomic modules is used to prove that there is a finite set of Noetherian operators that suffice to distinguish the elements in a primary ideal. READ MORE

  4. 7. Ekedahl Invariants, Veronese Modules and Linear Recurrence Varieties

    Author : Ivan Martino; Anders Björner; Volkmar Welker; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ekedahl Invariants; Noether Problem; Bogomolov Multiplier; Cyclic quotient singularities; Veronese Modules; Pile simplicial complex; Semigroup Rings; Betti Numbers; Mathematics; matematik;

    Abstract : The title of this thesis refers to the three parts of which it is composed.The first part concerns the Ekedahl Invariants, new geometric invariants for finite groups introduced in 2009 by Torsten Ekedahl. READ MORE

  5. 8. Around minimal Hilbert series problems for graded algebras

    Author : Lisa Nicklasson; Samuel Lundqvist; Christian Gottlieb; Uwe Nagel; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Graded algebras; Hilbert series; Lefschetz properties; Exterior algebra; Linear resolution; Mathematics; matematik;

    Abstract : The Hilbert series of a graded algebra is an invariant that encodes the dimension of the algebra's graded compontents. It can be seen as a tool for measuring the size of a graded algebra. This gives rise to the idea of algebras with a "minimal Hilbert series", among the algebras within a certain family. READ MORE