Sökning: "Theoretical Astrophysics"

Visar resultat 1 - 5 av 104 avhandlingar innehållade orden Theoretical 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. On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study

    Författare :Lars Mattsson; Susanne Höfner; Nils Bergvall; Kjell Olofsson; Martin Groenewegen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AGB stars; carbon stars; mass loss; stellar winds; circumstellar matter; cosmic dust; stellar evolution; nucleosynthesis; galactic chemical evolution; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi; Fysik; Physics;

    Sammanfattning : Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. LÄS MER

  4. 3. A Study of Grain Drift in C Stars : Theoretical Modeling of Dust-Driven Winds in Carbon-Rich Pulsating Giant Stars

    Författare :Christer Sandin; Susanne Höfner; Bengt Gustafsson; Lee Anne Willson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; hydrodynamics; radiative transfer; instabilities; dust formation; stars: AGB and post-AGB; stars: mass-loss; stars: variables: general; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : A major fraction of stars will pass through a short period of dramatic events in their final evolutionary stage. Low- to intermediate-mass stars, studied here, are stripped of their outer parts in a slow massive wind. This mass loss reshapes both the star and the surrounding medium. LÄS MER

  5. 4. Theoretical Studies of Binaries in Astrophysics

    Författare :Johann Dischler; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomi; Astronomy; Galaxy: centre; Stars: mass-loss; Binaries: close; Binaries: eclipsing;

    Sammanfattning : This thesis introduces and summarizes four papers dealing with computer simulations of astrophysical processes involving binaries. The first part gives the rational and theoretical background to these papers. In paper I and II a statistical approach to studying eclipsing binaries is described. LÄS MER

  7. 5. Theoretical and numerical bimetric relativity

    Författare :Francesco Torsello; Edvard Mörtsell; Eugeny Babichev; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spin-2 fields; extension of general relativity; ghost-free bimetric theory; Hassan–Rosen bimetric relativity; numerical relativity; teoretisk fysik; Theoretical Physics;

    Sammanfattning : General relativity (GR) is the standard physical theory describing gravitational interactions. All astrophysical and cosmological observations are compatible with its predictions, provided that unknown matter and energy components are included. These are called dark matter and dark energy. LÄS MER