Sökning: "Subatomic and Astrophysics"

Visar resultat 1 - 5 av 20 avhandlingar innehållade orden Subatomic and 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 :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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

  2. 2. Haystacks and Needles : Measuring the number of proton collisions in ATLAS and probing them for the production of new exotic particles

    Författare :Giulia Ripellino; Jonas Strandberg; Gabriella Pasztor; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Atomic; Subatomic and Astrophysics; Atomär fysik; subatomär fysik och astrofysik;

    Sammanfattning : This thesis describes my work on the ATLAS luminosity measurement and on two searches for physics beyond the Standard Model, performed using √s = 13 TeV proton-proton (pp) collision data recorded by the ATLAS detector at CERN during Run 2 of the LHC in the years 2015-2018ATLAS employs several detectors and methods to measure the relative luminosity and the absolute scale is determined using van der Meer scans during dedicated low-luminosity running periods in each year. The thesis presents the details of the track-counting method which is used to extrapolate the calibration to the high-luminosity physics data-taking regime. LÄS MER

  3. 3. 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 :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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. 4. Cosmic rays and shock physics in gamma-ray bursts

    Författare :Filip Samuelsson; Felix Ryde; Robert Mochkovitch; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; astrophysics; gamma-ray bursts; cosmic rays; radiation-mediated shocks; Atomic; Subatomic and Astrophysics; Atomär fysik; subatomär fysik och astrofysik;

    Sammanfattning : Gamma-ray bursts (GRBs) are the most luminous events in the known universe. Due to their tremendous energy output, they serve as laboratories of physics far beyond anything that we can hope to achieve in terrestrial experiments. LÄS MER

  5. 5. Measurements of Oscillator Strengths in Fe, Zr, Mo and Ce

    Författare :Carl Martin Sikström; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cerium; molybdenum; Atomic and molecular physics; Atom- och molekylärfysik; Condensed matter:electronic structure; magnetic and optical properties; electrical; magnetic resonance; supraconductors; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; astrophysics; magnetiska och optiska ; spektroskopi; oscillator strengths; supraledare; zirconium; magnetisk resonans; Fourier transform spectroscopy; branching fraction; radiative lifetimes; iron;

    Sammanfattning : Atomic data are needed in many different areas of science and technology. Examples of users are the astronomical community and the lighting industry. In this work, the purpose of the projects has been to produce reliable atomic data needed to solve specific astrophysical problems. LÄS MER