Next-to-simplified dark matter models

Dark matter constitutes the 27% of the energy content of the universe. However, the nature of dark matter is still a mystery. The Standard Model does not have any reasonable explanation to solve this problem, so the need for a theory beyond Standard Model is evident. In this context, simplified dark matter models are a good first attempt to solve this problem. But simplified models are limited by their simplicity and in many cases experimental searches put several bounds on them, constraining severely the parameter space. For these reasons, a step forward is needed. One way to do that is to enlarge the particle content of this kind of models, looking for more realistic configurations. For these reasons in this thesis we study two cases of portal models, a Higgs portal and a Z' portal, with a extended dark sector, obtaining interesting phenomenology in both cases.