Sökning: "Gert Brodin"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Gert Brodin.

  1. 1. The effect of spacecraft charging on low-energy ion measurements around comet 67P/Churyumov-Gerasimenko

    Författare :Sofia Bergman; Gabriella Stenberg Wieser; Martin Wieser; Gert Brodin; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Spacecraft charging; low-energy ions; space physics; plasma physics; comet; Rosetta; SPIS; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : A spacecraft in space interacts with the surrounding environment and aqcuires an electrostatic potential. Charged particles are constantly bombarding the surface of the spacecraft, and at the same time solar EUV radiation induces photoemission, causing electrons to be emitted from the surface. LÄS MER

  2. 2. Quantum Kinetic Theory for Plasmas : spin, exchange, and particle dispersive effects

    Författare :Robin Ekman; Gert Brodin; Jens Zamanian; Bengt Eliasson; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; teoretisk fysik; Theoretical Physics;

    Sammanfattning : This thesis is about developing and studying quantum mechanical models of plasmas. Quantum effects can be important at high densities, at low temperatures, and in strong electromagnetic fields, in various laboratory and astrophysical systems. LÄS MER

  3. 3. Perturbative Methods in General Relativity

    Författare :Daniel Eriksson; Michael Bradley; Gert Brodin; Lászlo Árpád Gergely; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; General relativity; perturbation theory; photon-photon scattering; cosmology; FRW models with cosmological constant; Bianchi type V; slowly rotating stars; Hartle formalism; Physics; Fysik;

    Sammanfattning : Einstein's theory of general relativity is a cornerstone in the process of gaining increased understanding about problems of gravitational nature. It can be applied to problems on the huge length scales of cosmology and as far as we know it does not break down before the Planck scale is approached. LÄS MER

  4. 4. Gravitational perturbations in plasmas and cosmology

    Författare :Mats Forsberg; Gert Brodin; Michael Bradley; Christopher Clarkson; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; general relativity; cosmology; gravitational waves; plasma; electromagnetic waves; nonlinear waves; Plasma physics; Plasmafysik; Theory of relativity; gravitation; Relativitetsteori; gravitation; Cosmology; Kosmologi; teoretisk fysik; Theoretical Physics;

    Sammanfattning : Gravitational perturbations can be in the form of scalars, vectors or tensors. This thesis focuses on the evolution of scalar perturbations in cosmology, and interactions between tensor perturbations, in the form of gravitational waves, and plasma waves. LÄS MER

  5. 5. Ultra-intense laser-plasma interaction for applied and fundamental physics

    Författare :Arkady Gonoskov; Mattias Marklund; Gert Brodin; Vladimir Tikhonchuk; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; ultra-intense laser; femtosecond pulse; plasma; relativistic phenomena; laser-driven acceleration; attosecond pulse generation; radiation reaction; fysik; Physics;

    Sammanfattning : Rapid progress in ultra-intense laser technology has resulted in intensity levels surpassing 1022 W/cm2, reaching the highest possible density of electromagnetic energy amongst all controlled sources available in the laboratory. During recent decades, fast growth in available intensity has stimulated numerous studies based on the use of high intensity lasers as a unique tool for the initiation of nonlinear behavior in various basic systems: first molecules and atoms, then plasma resulting from the ionization of gases and solids, and, finally, pure vacuum. LÄS MER