Thesis

Light and Ultralight Dark Matter: exploring novel synergies between particle physics, strong gravity and cosmology

• Call:

  PT-CERN Call 2022/2

• Academic Year:

  2022

• Domain:

  Astroparticle Physics

• Supervisor:

  António Morais

• Co-Supervisor:

  Roman Pasechnik

• Institution:

  Universidade de Aveiro

• Host Institution:

  CIDMA - Centro de Investigação em Matemática e Aplicações da Universidade de Aveiro

• Abstract:

  This thesis proposes a synergy between the areas of strong gravity, cosmology and particle physics in order to explore the Feebly Interacting Particle (FIP) DM paradigm. Contrary to the typical approach taken by the strong gravity community, this thesis aims the construction of concrete particle physics models where ultralight DM particles can emerge either as pseudo-goldstone bosons or as vector bosons, in such a way that they can reveal themselves in the form of stable halos around compact astrophysical objects. However, such halos are only viable when the Compton wavelength of the field approximately matches the gravitational scale of the compact object. For the known astrophysical objects, such as black holes, whose mass is in the range of 1 and 10 to the 10 solar masses, this means that such bosonic particles must have masses between 10 to the minus 10 and 10 to the minus 20 eV. The presence of an ultralight bosonic sector implies further bosonic particles that are not necessarily ultralight, and perhaps at the reach of the LHC if their mass is larger than 1 GeV. Additionally, unstable topological defects may emerge in a pseudo-Nambu-Goldstone (pNG) DM cosmology, which produce gravitational waves in the final state and can be probed by the current experiments. Furthermore, for models featuring neutrino mass generation mechanisms, a sterile neutrino can also become a fermionic DM candidate with masses in the keV-MeV range. In this thesis, a catalog of models that can consistently predict light and ultralight bosons as well as sterile neutrinos will be constructed. These are extraordinary candidates to offer multi-component DM which will be studied and confronted with data both from the gravitational, collider, and direct detection channels.