Phenomenology of dark matter indirect detection
- Authors
- Publication Date
- Sep 16, 2024
- Source
- HAL
- Keywords
- Language
- English
- License
- Unknown
- External links
Abstract
Among the open problems of modern physics, dark matter (DM) is one of the most fascinating. It explains several gravitational anomalies observed at different scales: the flatness of rotation curves of spiral galaxies, the dynamics of galaxy clusters, the distribution of large-scale structures in the Universe, and the anisotropies in the temperature of the cosmic microwave background. Precise measurements of the latter, possibly combined with other techniques, show that DM constitutes about a quarter of the Universe's energy budget. Although we have reliable observational evidence of DM's existence, its nature remains a mystery, as no observation has yet shown that DM can interact with ordinary matter other than gravitationally. Numerous hypotheses about its nature remain. DM could exist as elementary particles not included in the Standard Model of particle physics, or as macroscopic compact objects such as primordial black holes (PBH). To reveal the nature of DM, or to rule out hypotheses concerning it, several observational techniques are available. In this thesis, we focus on the method of indirect detection, which involves looking for signals of the annihilation or decay of DM in the form of charged cosmic rays, photons or neutrinos. Each product carries different types of information. Photons and neutrinos, being neutral particles, can propagate without being deflected by the surrounding magnetic fields, making it easier to trace their source of emission. Charged cosmic rays, on the other hand, may consist of antimatter, which is less likely produced by astrophysical processes and can therefore be detected with a low background. In this thesis, we study the emission of secondary photons by the interaction of DM products with the galactic environment. Specifically, we consider the case in which DM is a particle with a mass below a GeV. The electrons and positrons produced could interact with ambient photons in the galaxy, producing X-rays through inverse Compton scattering. The prediction of the spectrum of this radiation, compared with data from X-ray observatories, provides strong constraints on this type of DM. Similarly, we apply this same principle to the case of PBH evaporation in order to impose strong constraints on them.
