Search for dissertations about: "Volkmar Welker"

Found 5 swedish dissertations containing the words Volkmar Welker.

  1. 1. On Face Vectors and Resolutions

    Author : Afshin Goodarzi; Anders Björner; Volkmar Welker; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : This thesis consist of the following three papers.Convex hull of face vectors of colored complexes. In this paper we verify a conjecture by Kozlov (Discrete ComputGeom18(1997) 421–431), which describes the convex hull of theset of face vectors ofr-colorable complexes onnvertices. READ MORE

  2. 2. Topological and Shifting Theoretic Methods in Combinatorics and Algebra

    Author : Afshin Goodarzi; Anders Björner; Volkmar Welker; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Matematik; Mathematics;

    Abstract : This thesis consists of six papers related to combinatorics and commutative algebra.In Paper A, we use tools from topological combinatorics to describe the minimal free resolution of ideals with a so called regular linear quotient. Our result generalises the pervious results by Mermin and by Novik, Postnikov & Sturmfels. READ MORE

  3. 3. Ekedahl Invariants, Veronese Modules and Linear Recurrence Varieties

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

    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

  4. 4. Around power ideals : From Fröberg's conjecture to zonotopal algebra

    Author : Gleb Nenashev; Boris Shapiro; Volkmar Welker; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; matematik; Mathematics;

    Abstract : In this thesis we study power algebras, which are quotient of polynomial rings by power ideals. We will study Hilbert series of such ideals and their other properties. We consider two important special cases, namely, zonotopal ideals and generic ideals. Such ideals have a lot combinatorial properties. READ MORE

  5. 5. On a class of commutative algebras associated to graphs

    Author : Gleb Nenashev; Boris Shapiro; Volkmar Welker; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : In 2004 Alexander Postnikov and Boris Shapiro introduced a class of commutative algebras for non-directed graphs. There are two main types of such algebras, algebras of the first type count spanning trees and algebras  of the second type count spanning forests. READ MORE