Sökning: "Particle astrophysics"

Visar resultat 1 - 5 av 65 avhandlingar innehållade orden Particle astrophysics.

  1. 1. Supersymmetry vis-à-vis Observation : Dark Matter Constraints, Global Fits and Statistical Issues

    Författare :Yashar Akrami; Joakim Edsjö; Lars Bergström; Roberto Trotta; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; supersymmetry; cosmology of theories beyond the Standard Model; dark matter; gamma rays; dwarf galaxies; direct detection; statistical techniques; scanning algorithms; genetic algorithms; statistical coverage; Astroparticle physics; Astropartikelfysik; Cosmology; Kosmologi; Astroparticle physics; Astropartikelfysik; teoretisk fysik; Theoretical Physics;

    Sammanfattning : Weak-scale supersymmetry is one of the most favoured theories beyond the Standard Model of particle physics that elegantly solves various theoretical and observational problems in both particle physics and cosmology. In this thesis, I describe the theoretical foundations of supersymmetry, issues that it can address and concrete supersymmetric models that are widely used in phenomenological studies. LÄS MER

  3. 2. Searches for Particle Dark Matter : Dark stars, dark galaxies, dark halos and global supersymmetric fits

    Författare :Pat Scott; Joakim Edsjö; Lars Bergström; Jan Conrad; Dan Hooper; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dark matter; supersymmetry; gamma rays; dwarf galaxies; stellar evolution; cosmological perturbations; phase transitions; statistical techniques; Astroparticle physics; Astropartikelfysik; Astroparticle physics; Astropartikelfysik; Cosmology; Kosmologi; Elementary particle physics; Elementarpartikelfysik; Computational physics; Beräkningsfysik; Formation and development of stars; Stjärnors bildning och utveckling; High energy astrophysics; Högenergiastrofysik; teoretisk fysik; Theoretical Physics;

    Sammanfattning : The identity of dark matter is one of the key outstanding problems in both particle and astrophysics. In this thesis, I describe a number of complementary searches for particle dark matter. LÄS MER

  4. 3. Extending the observational reach of core-collapse supernovae for IceCube using high-energy neutrinos

    Författare :Nora Valtonen-Mattila; Erin O'Sullivan; Timothy Linden; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Neutrino physics; Neutrino astrophysics; Supernovae; Core-collapse supernovae; Particle astrophysics; Fysik; Physics;

    Sammanfattning : Neutrino telescopes such as IceCube monitor for low-energy neutrinos O(10 MeV) produced in nuclear processes during core-collapse in supernovae. The detection horizon to the neutrino burst is 50 kpc, the distance to the Magellanic Clouds. LÄS MER

  5. 4. Microphysical Conditioning of Gamma-Ray Burst Shocks

    Författare :Jacob Trier Frederiksen; Claes Fransson; Åke Nordlund; Mikhail V. Medvedev; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic fields; particle acceleration; plasma instabilities; gamma-ray bursts; collisionless shocks; relativistic outflows; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; astronomi;

    Sammanfattning : Gamma-Ray Bursts (GRBs) are believed to be connected with either collapse of massive stars or – in some cases – coalescing neutron stars, both of which cause extreme relativistic explosions observable from the entire Universe. GRBs produce rapid flashes of high energy radiation, extending up to 2MeV in photon energies: as much energy per photon as the rest mass of 4 electrons. LÄS MER

  7. 5. Dissipative formation of galaxies in hierarchical cosmology

    Författare :John Hultman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; merical methods; hydrodynamics; galaxies: formation; galaxies: elliptical; galaxies: structure; star formation; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : A description and detailed tests of a numerical code for simulations of galaxy formation is presented. The dynamics is followed with fully adaptive and Lagrangian Smooth Particle Hydrodynamics (SPH) combined with a gravitational tree method. The severe numerical problem of sub-resolution clustering is solved by merging of gas particles. LÄS MER