Search for dissertations about: "vertex scattering matrix"

Found 4 swedish dissertations containing the words vertex scattering matrix.

  2. 1. 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

  4. 2. First principles methods for electronic structure calculations of solids

    Author : Martin Springer; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; screened interaction; T-matrix; vertex function; GW approximation; Green function; density functional theory; gradient expansion; order N method; Physics; Fysik;

    Abstract : A straightforward gradient expansion of the exchange energy of a perturbed electron gas is performed. Studied perturbations range from very weak to those that produce, e.g., a silicon-like band structure with a band gap. READ MORE

  5. 3. Multi-Meson Dynamics in Chiral Perturbation Theory

    Author : Mattias Sjö; Partikel- och kärnfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Spridningsamplituder; Effektiv Fältteori; Spontant symmetribrott; Ickelinjära sigmamodellen; Kirala Lagrangianer; Hadronspektroskopi; Strukturer och Interaktioner; Gitter-QCD; Scattering amplitudes; Effective Field Theories; Spontaneous Symmetry Breaking; Nonlinear sigma model; Chiral Lagrangians; Hadronic Spectroscopy; Structure and Interactions; Lattice QCD;

    Abstract : This thesis concerns scattering of light mesons in the case where the number of external particles exceeds four (that is, three or more particles in the initial or final state), calculated using chiral perturbation theory.This is both of theoretical interest in the study of scattering amplitudes, and relevant for systems of three or more pions simulated using lattice quantum chromodynamics. READ MORE

  6. 4. Inverse Problems for Graph Laplacians

    Author : Marlena Nowaczyk; Matematik LTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Spectral theory; Laplace operator; Trace formula; Quantum graphs;

    Abstract : This thesis is devoted to inverse spectral problems for Laplace operators on metric graphs, and it is based on the following papers: Paper I - P. Kurasov and M. Nowaczyk 2005 Inverse spectral problem for quantum graphs J. Phys. READ MORE