A Common Origin for WIMP Dark Matter and the Baryon Asymmetry of the Universe

The Standard Model of particle physics, despite its remarkable success, fails to explain two key phenomena in cosmology: the nature of dark matter (DM) and the baryon asymmetry of the Universe. These two issues highlight the need for physics beyond the SM. Weakly Interacting Massive Particles (WIMPs) have long been considered among the main candidates for DM due to the so-called "WIMPs miracle", by which their relic abundance naturally matches the observed dark matter density. On the other hand, the Sakharov conditions provide a theoretical framework for generating the baryon asymmetry, through a Baryogenesis process, although their realization often requires extensions to the SM. This thesis explores the interesting possibility of a unified solution to these problems via a "WIMPy Baryogenesis". This mechanism proposes that WIMPs annihilations satisfy the Sakharov conditions, generating a baryon asymmetry besides producing the dark matter relic density. The theoretical framework is developed through Boltzmann equations describing particle number densities and asymmetry evolution. It is shown the importance of the freeze-out moment of the washout processes in order to get the expected baryon asymmetry, which translates into a relation between the masses involved. It is proposed one possible model in which WIMPs annihilate directly into quarks, plus a new massive baryon field. Finally, the main dependencies of the final value of the asymmetry are analyzed.