Sökning: "lrs"

Visar resultat 1 - 5 av 6 uppsatser innehållade ordet lrs.

  1. 1. On the Interaction Between Electromagnetic, Gravitational, and Plasma Related Perturbations on LRS Class II Spacetimes

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Philip Semrén; [2021]
    Nyckelord :;

    Sammanfattning : In this thesis, we investigate the interaction between electromagnetic, gravitational, and plasma related perturbations on homogeneous and hypersurface orthogonal Locally Rotationally Symmetric (LRS) class II spacetimes. By using these spacetimes, which allow for the inclusion of a non-zero magnetic field, as backgrounds in a perturbative approach, we are able to see interactions between the electromagnetic and gravitational variables already to first order in the perturbations. LÄS MER

  3. 2. Dissipative Perturbations on LRS Class II Cosmologies Using the 1+1+2 Covariant Split of Spacetime

    Master-uppsats, Umeå universitet/Institutionen för fysik

    Författare :Philip Semrén; [2020]
    Nyckelord :;

    Sammanfattning : By including dissipative fluxes in the description, this thesis extends previous results regarding first order perturbations on homogeneous and hypersurface orthogonal locally rotationally symmetric (LRS) class II cosmologies using the 1 + 1 + 2 covariant split of spacetime. Whereas previous works consider perturbations of perfect fluid type, perturbations pertaining to heat flux and fluid viscosity are here studied with the aim to ascertain their effect on the evolution of the fluid vorticity. LÄS MER

  4. 3. Vorticity and Gravitational Wave Perturbations on Cosmological Backgrounds Using the 1+1+2 Covariant Split of Spacetime

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Robin Törnkvist; [2018]
    Nyckelord :;

    Sammanfattning : In this thesis we consider perturbations of a perfect fluid on locally rotationally symmetrical (LRS) class II cosmological backgrounds, with a nonvanishing vorticity of the fluid on the perturbed model. The method used is based on the 1+1+2 covariant decomposition of spacetime, motivated by the assumption of anisotropic expansion, followed by a harmonic decomposition of all gauge invariant quantities. LÄS MER

  5. 4. Imaging of the Temperature Distribution in a Catalyst Test Chamber using Laser Rayleigh Scattering

    Kandidat-uppsats, Lunds universitet/Förbränningsfysik; Lunds universitet/Fysiska institutionen

    Författare :Sebastian Pfaff; [2015]
    Nyckelord :rayleigh scattering; combustion; laser induced fluorescence; catalyst; catalysis; laser rayleigh scattering; lif; lrs; Physics and Astronomy;

    Sammanfattning : In order to accurately measure the effect on the gas concentration around catalysts in a high pressure environment using laser based techniques such as Laser Induced Florescence (LIF), accurate temperature maps of the test chamber used are required. In order to create such temperature maps Laser Rayleigh Scattering (LRS) is utilized which allows for a non-intrusive probing of temperatures in a two dimensional measurement area. LÄS MER

  7. 5. Dynamics of Discrete Irregular Cosmological Models

    Master-uppsats, Stockholms universitet/Fysikum

    Författare :Shan Williams Jolin; [2014]
    Nyckelord :cosmology; discrete; irregular; simulations; dark energy; LRS curve; dynamics; Schwarzschild black holes;

    Sammanfattning : This thesis investigates the dynamics of a set of 8-600 Schwarzschild masses, randomly distributed inside cells which tessellate a 3-sphere. Furthermore the contents of each cell are mirror images of its neighbor. LÄS MER