Search for dissertations about: "graph enumeration"

Found 3 swedish dissertations containing the words graph enumeration.

  2. 1. Enumeration on words, complexes and polytopes

    Author : Ragnar Freij; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Simplicial complex; discrete Morse theory; Hansen polytope; $3^d$-conjecture; split graph; derangement; pattern containment; pattern packing; composition.; composition.;

    Abstract : This thesis presents four papers, studying enumerative problems on combinatorial structures. The first paper studies Forman's discrete Morse theory in the case where a group acts on the underlying complex. READ MORE

  4. 2. Snarks : Generation, coverings and colourings

    Author : Jonas Hägglund; Roland Häggkvist; Klas Markström; Luis Goddyn; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Snarks; cubic graphs; enumeration; cycle covers; perfect matching covers; Fulkerson s conjecture; strong cycle double cover conjecture; cycle decompositions; stable cycles; oddness; circumference; uncolourability measures; Mathematics; matematik;

    Abstract : For a number of unsolved problems in graph theory such as the cycle double cover conjecture, Fulkerson's conjecture and Tutte's 5-flow conjecture it is sufficient to prove them for a family of graphs called snarks. Named after the mysterious creature in Lewis Carroll's poem, a \emph{snark} is a cyclically 4-edge connected 3-regular graph of girth at least 5 which cannot be properly edge coloured using three colours. READ MORE

  5. 3. Topics in algorithmic, enumerative and geometric combinatorics

    Author : Ragnar Freij; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Discrete Morse theory; simplicial G-complex; centrally symmetric polytope; split graph; derangement; pattern packing; composition; finite poset; optimal stopping; secretary problem.; finite poset;

    Abstract : This thesis presents five papers, studying enumerative and extremal problems on combinatorial structures. The first paper studies Forman's discrete Morse theory in the case where a group acts on the underlying complex. READ MORE