Generation of dark matter in the early universe from BSM models

Abstract

For several decades the nature of Dark Matter (DM) has been elusive to physics. Explanations for its evidences have been stacked up and most of them require new particle physics. In this work, we explore the standard thermal WIMP DM scenario as well as a non-thermal alternative for DM production. For the former framework, we introduce the foundations for its understanding: the FLRW metric for an isotropic and homogeneous universe, the Λ-CDM cosmological model and thermodynamics of the early universe. We also present theoretical tools such as the Boltzmann equation for the DM relic density calculation, after which experimental detection tests are discussed. Two applications of the thermal WIMP scenario are dealt with: (i) a study of a more precise calculation of the Standard Model (SM) degrees of freedom, discussing thereafter the impact of that evaluation on the DM relic density calculation in a model-independent way, comparing it to indirect detection tests; (ii) a BSM (Beyond SM) model with a B - L extension, in which the possibility of a fermionic majorana DM is considered, and the cross section of the candidate is compared with spin-independent direct detection upper bounds.<br /> In the end we explore the nonthermal scenario, where we consider fields motivated by string theory, the KL sector. Therein we introduce the feature of uplifting, whereby the AdS originated solely by the KL potential can be lifted to the dS vacuum by the addition of the ISS sector. Afterwards, the ISS fields oscillations and their subsequent decays are analyzed within a context of small entropy production as well as sufficient neutralino DM generation.