Search for dissertations about: "singularity expansion"

Showing result 1 - 5 of 6 swedish dissertations containing the words singularity expansion.

  2. 1. Elastic Wave Scattering by Closed Cracks and Thin Flaws - Multiple Scattering and Resonances

    Author : Arne S. Eriksson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SH-wave; evaluation of materials; direct integral equation; singularity expansion; ultrasonic testing;

    Abstract : In this thesis we study elastic wave scattering by thin flaws and closed cracks, which finds applications in ultrasonic testing and evaluation of materials. First we consider the scattering of an SH-wave by a thin finite elastic layer between two elastic half-spaces. READ MORE

  4. 2. Singular Fluxes in Ten and Eleven Dimensions : Sources, Singularities, Fluxes and Spam

    Author : Johan Blåbäck; Ulf Danielsson; Niels Obers; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical Physics; Teoretisk fysik;

    Abstract : The energy content of our present universe is dominated by the dark-energy, or vacuum energy, which provides accelerated cosmic expansion. Dark energy has a possible effective explanation through a positive cosmological constant. READ MORE

  5. 3. On various aspects of extended objects

    Author : Mariusz Hynek; Jens Hoppe; Volker Bach; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Abstract : This thesis concerns classical and quantum aspects of minimal manifolds embedded in flat Minkowski space. In particular, we study the Lie algebra of diffeomorphisms on 2 dimensional compact manifolds as well as discuss singularity formation for relativistic minimal surfaces in co-dimension one. READ MORE

  6. 4. Quiescent regimes in cosmology

    Author : Hans Oude Groeniger; Hans Ringström; Mattias Dahl; Todd Oliynyk; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quiescence; Bianchi spacetimes; big bang formation; G2 cosmology; Wainwright-Hsu variables; Klein-Gordon equation; Matematik; Mathematics;

    Abstract : This thesis is about cosmological solutions to Einstein’s equations of general relativity, in particular spacetimes whose mean curvature diverges. Moreover, we consider anisotropic spacetimes with big bang singularities. In this setting the singularity is expected to generically be oscillatory if no matter is present. READ MORE

  7. 5. Strong Cosmic Censorship and Cosmic No-Hair in spacetimes with symmetries

    Author : Katharina Maria Radermacher; Hans Ringström; James Isenberg; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cosmic Censorship; Cosmic No-Hair; Big Bang; symmetry; Bianchi; T2-symmetry; Gowdy; general relativity; cosmology; late time; initial time; asymptotic behaviour; perfect fluid; scalar field; Einstein equations; Mathematics; Matematik;

    Abstract : This thesis consists of three articles investigating the asymptotic behaviour of cosmological spacetimes with symmetries arising in Mathematical General Relativity.In Paper A and B, we consider spacetimes with Bianchi symmetry and where the matter model is that of a perfect fluid. READ MORE