Search for dissertations about: "cubic graphs"

Found 4 swedish dissertations containing the words cubic graphs.

  1. 1. 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

  2. 2. Random railways and cycles in random regular graphs

    Author : Hans Garmo; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Random railway; connectivity number; random regular graph; long cycles; asymptotic distribution. 1991 Mathematics Subject Classification. Primary 60F05; 60C05; 05C38; 05C80; 05C40; 05C45; MATEMATIK; MATHEMATICS; MATEMATIK; matematisk statistik; Mathematical Statistics;

    Abstract : In a cubic multigraph certain restrictions on the paths are made to define what is called a railway. Due to these restrictions a special kind of connectivity is defined. As the number of vertices tends to infinity, the asymptotic probability of obtaining an, in this sense, connected random cubic multigraph is shown to be 1/3. READ MORE

  3. 3. On the Ising problem and some matrix operations

    Author : Daniel Andrén; Roland Häggkvist; Henrik Eriksson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ising problem; phase tansition; matrix multiplicatoin; matrix inversion; Discrete mathematics; Diskret matematik;

    Abstract : The first part of the dissertation concerns the Ising problem proposed to Ernst Ising by his supervisor Wilhelm Lenz in the early 20s. The Ising model, or perhaps more correctly the Lenz-Ising model, tries to capture the behaviour of phase transitions, i.e. how local rules of engagement can produce large scale behaviour. READ MORE

  4. 4. Asymptotics and dynamics in first-passage and continuum percolation

    Author : Daniel Ahlberg; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; first-passage percolation; noise sensitivity; continuum percolation; Gilbert model; limit theorems; shape theorem; stopped random walks; large deviations; dynamical percolation; continuum percolation;

    Abstract : This thesis combines the study of asymptotic properties of percolation processes with various dynamical concepts. First-passage percolation is a model for the spatial propagation of a fluid on a discrete structure; the Shape Theorem describes its almost sure convergence towards an asymptotic shape, when considered on the square (or cubic) lattice. READ MORE