Search for dissertations about: "graphs"

Showing result 11 - 15 of 296 swedish dissertations containing the word graphs.

  2. 11. Extremal eigenvalues and geometry of quantum graphs

    Author : Andrea Serio; Pavel Kurasov; Annemarie Luger; Evans Harrell; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum graphs; spectral estimates; trace formula; Euler characteristic; Mathematics; matematik;

    Abstract : This thesis consists of four papers concerning topics in the spectral theory of quantum graphs, which are differential operators on metric graphs.In paper I we present a family of graphs with an arbitrary number of cycles for which a certain eigenvalue upper estimate is sharp. READ MORE

  4. 12. Quantum Graphs and Equi-transmitting Scattering Matrices

    Author : Wyclife Ogik Rao; Pavel Kurasov; Rikard Bogvad; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum graphs; vertex scattering matrix; equi-transmitting matrices.; matematik; Mathematics;

    Abstract : The focus of this study is scattering matrices in the framework of quantum graphs,more precisely the matrices which describe equi-transmission. They are unitary andHermitian and are independent of the energies of the associated system. READ MORE

  5. 13. Degrees in Random Graphs and Tournament Limits

    Author : Erik Thörnblad; Svante Janson; Erik Broman; Daniel Kráľ; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Random graphs; degree distributions; degree sequences; graph limits; tournaments; Mathematics; Matematik;

    Abstract : This thesis consists of an introduction and six papers on the topics of degree distributions in random graphs and tournaments and their limits.The first two papers deal with a dynamic random graph, evolving in time through duplication and deletion of vertices and edges. In Paper I we study the degree densities of this model. READ MORE

  6. 14. Spectral estimates and Ambartsumian-type theorems for quantum graphs

    Author : Rune Suhr; Pavel Kurasov; Annemarie Luger; Alexei Rybkin; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Spectral estimates; quantum graphs; Ambartsumian; trigonometric polynomials; Mathematics; matematik;

    Abstract : This thesis consists of four papers and deals with the spectral theory of quantum graphs. A quantum graph is a metric graph equipped with a self-adjoint Schrödinger operator acting on functions defined on the edges of the graph subject to certain vertex conditions. READ MORE

  7. 15. Codes on Graphs and More

    Author : Florian Hug; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; convolutional codes; woven graph codes; Low-density parity-check LDPC codes; tailbiting codes; bit error probability; MacWilliams Identity;

    Abstract : Modern communication systems strive to achieve reliable and efficient information transmission and storage with affordable complexity. Hence, efficient low-complexity channel codes providing low probabilities for erroneous receptions are needed. READ MORE