Sökning: "Jörgen Backelin"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Jörgen Backelin.

  1. 1. Some homological results for graded or commutative rings

    Författare :Jörgen Backelin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  3. 2. Chordal and Complete Structures in Combinatorics and Commutative Algebra

    Författare :Eric Emtander; Jörgen Backelin; Ralf Fröberg; Bernd Sturmfels; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Betti numbers; chordal hypergraphs; complete hypergraphs; hypercycle; line hypergraph; numerical monoids; positive affine monoids; Other mathematics; Övrig matematik; Mathematics; matematik;

    Sammanfattning : This thesis is divided into two parts. The first part is concerned with the commutative algebra of certain combinatorial structures arising from uniform hypergraphs. The main focus lies on two particular classes of hypergraphs called chordal hypergraphs and complete hypergraphs, respectively. LÄS MER

  4. 3. On hypergraph algebras

    Författare :Eric Emtander; Jörgen Backelin; Ralf Fröberg; Jakob Jonsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; matematik;

    Sammanfattning : .... LÄS MER

  5. 4. On linear graph invariants related to Ramsey and edge numbers : or how I learned to stop worrying and love the alien invasion

    Författare :Oliver Krüger; Jörgen Backelin; Alexander Engström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ramsey number; edge number; minimal Ramsey graph; independence number; clique number; Turán s theorem; crochet pattern; H13-pattern; linear graph invariant; triangle-free graph; Mathematics; matematik;

    Sammanfattning : In this thesis we study the Ramsey numbers, R(l,k), the edge numbers, e(l,k;n) and graphs that are related to these. The edge number e(l,k;n) may be defined as the least natural number m for which all graphs on n vertices and less than m edges either contains a complete subgraph of size l or an independent set of size k. LÄS MER

  7. 5. On minimal triangle-free Ramsey graphs

    Författare :Oliver Krüger; Jörgen Backelin; Klas Markström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : A graph G is called a minimal Ramsey (3, k; n)-graph if it has the least amount of edges, e(3, k; n), possible given that G is triangle-free, has independence number α(G) < k an has n vertices. The numbers e(3, k; n) and the minimalRamsey graphs are directly related to the Ramsey numbers R(3, k). LÄS MER