Beyond Minimal Models in Astroparticle Physics and LHC phenomology

I will work on models of new physics that address shortcomings of the standard model of particle physics when its predictions are compared with experimental data. In the beginning of my PhD, I will study models that address observables related to astro-particle physics, in particular on the observed dark matter in our universe or the baryon to photon ratio. To arrive at conclusions that are valid for a wider class of models, I will work on a minimal model approach that encompasses additional constraints from model building. I.e. I will, for example, work on extensions of minimal models that are renormalisable and mimic the phenomenology of complete models of new physics and on effective descriptions of new physics. This will enable me to study correlations of astro-particle observables with data gathered from lab based experiments. An open research question is the generalisability of these correlations and the above described model setup should allow me to answer this question. As a starting project, I will be looking into singlet extension of the standard model coupled to right-handed neutrinos. This is a renormalisable model that in different parts of the parameter space can feature dark matter, produce baryon asymmetry via low scale leptogenesis, feature a first-order electroweak phase transition in the early universe, and be testable at colliders. I will study if several of these can be achieved simultaneously in the minimal framework and produce interesting experimental signals, and potential extensions of the minimal framework. The project will be supervised by Tommi Alanne (40%), Oliver Fischer (20%) and Martin Gorbahn (40%), who provide the expertise in astro-paricle physics, collider physics, and effective descriptions of new physics.