Browsing NTNU Open by Author "Tjemsland, Jonas"

Now showing items 1-14 of 14

    • Adiabatic axion-photon mixing near neutron stars 

      Tjemsland, Jonas; McDonald, Jamie; Witte, Samuel J. (Peer reviewed; Journal article, 2024)

    • Alternative coalescence model for deuteron, tritium, helium-3 and their antinuclei 

      Kachelriess, Michael; Ostapchenko, Sergey; Tjemsland, Jonas (Peer reviewed; Journal article, 2020)
      Antideuteron and antihelium nuclei have been proposed as a detection channel for dark matter annihilations and decays in the Milky Way, due to the low astrophysical background expected. To estimate both the signal for ...

    • Antinuclei as a Signature of Dark Matter 

      Tjemsland, Jonas (Master thesis, 2019)
      Antideuteron og antihelium er blitt foreslått som en deteksjonskanal for spalting og annihilasjon av mørk materie i Melkeveien på grunn av en forventet lav astrofysisk bakgrunnstøy. I dag er det vanlig å bruke en standard ...

    • Detecting ALP wiggles at TeV energies 

      Kachelriess, Michael; Tjemsland, Jonas (Peer reviewed; Journal article, 2024)
      Axions and axion-like-particles (ALPs) are characterised by their two-photon coupling, which entails so-called photon-ALP oscillations as photons propagate through a magnetic field. These oscillations lead to distinctive ...

    • Formation models for cosmic ray antinuclei 

      Kachelriess, Michael; Ostapchenko, Sergey; Tjemsland, Jonas (Peer reviewed; Journal article, 2022)
      The expected low background of light antinuclei, such as antideuteron and antihelium-3, makes them ideal detection channels for exotic physics, such as dark matter annihilations. At the same time, their small binding ...

    • Formation of light (anti)nuclei 

      Tjemsland, Jonas (Peer reviewed; Journal article, 2021)
      The production mechanism of light nuclei, such as deuteron, helium-3, tritium and their antiparticles, has recently attracted an increased attention from the astroparticle and heavy ion communities. The expected low ...

    • Meson production in air showers and the search for light exotic particles 

      Kachelriess, Michael; Tjemsland, Jonas (Peer reviewed; Journal article, 2021)
      Decays of mesons produced in cosmic ray induced air showers in Earth’s atmosphere can lead to a flux of light exotic particles which can be detected in underground experiments. We evaluate the energy spectra of the light ...

    • Nuclear coalescence and collective behaviour in small interacting systems 

      Kachelriess, Michael; Ostapchenko, Sergey; Tjemsland, Jonas (Peer reviewed; Journal article, 2022)
      The production of light nuclei in particle collisions can be described as the coalescence of nucleons into nuclei. In most coalescence models used in heavy ion collisions, the probability for coalescence is controlled ...

    • Photon-ALP oscillations at CTA energies 

      Kachelriess, Michael; Tjemsland, Jonas (Peer reviewed; Journal article, 2023)
      Axions and axion-like-particles (ALPs) are well motivated beyond the standard model particles that can explain a variety of unsolved problems in physics, such as the strong CP problem and the nature of dark matter. These ...

    • Photon-ALP oscillations at TeV energies 

      Kachelriess, Michael; Tjemsland, Jonas (Peer reviewed; Journal article, 2022)
      Axion and axion-like-paricles (ALPs) are well motivated cold dark matter candidates. Nevertheless, an astoundingly huge parameter space remains unexplored despite much effort, ranging from fuzzy dark matter at ma∼10−22 eV ...

    • Photon-ALP oscillations with ELMAG 

      Kachelriess, Michael; Tjemsland, Jonas (Peer reviewed; Journal article, 2022)
      ELMAG is a Monte Carlo program made to simulate electromagnetic cascades initiated by high-energy photons interacting with the extragalactic background light. Photons propagating in an external magnetic field may oscillate ...

    • Probing dark matter with astroparticles 

      Tjemsland, Jonas (Doctoral theses at NTNU;2023:240, Doctoral thesis, 2023)
      There is an enormous amount of evidence for the existence of dark matter, from scales ranging from the faintest dwarf galaxies to the Universe as a whole. However, its nature remains a mystery. This thesis is a part of the ...

    • Reacceleration of charged dark matter 

      Kachelriess, Michael; Tjemsland, Jonas (Peer reviewed; Journal article, 2020)
      Charged particles scattering on moving inhomogenities of the magnetised interstellar medium can gain energy through the process of second-order Fermi acceleration. This energy gain depletes in turn the magnetic wave spectrum ...

    • Revisiting cosmic ray antinuclei fluxes with a new coalescence model 

      Kachelriess, Michael; Ostapchenko, Sergey; Tjemsland, Jonas (Peer reviewed; Journal article, 2020)
      Antideuteron and antihelium nuclei have been proposed as promising detection channels for dark matter because of the low astrophysical backgrounds expected. To estimate both potential exotic contributions and their ...