Peeping at the Universe through the keyhole: cosmology with neutrons

The Universe and its history are at the same time very well understood and a big mystery. We have amazing tools from satellites to observatories to weigh the universe as it is today and also as it was in the past. But the content of the Universe can simply not be explained by physicists. To get the full picture, we need to identify and understand the interactions at play throughout the life of the Universe. This is the meeting point between particle physics and cosmology. At this meeting point stands the neutron, a very common particle that we can uniquely use in high precision experiments.
I will present how experiments searching for a permanent electric dipole moment of the neutron (nEDM) aim at discovering new sources of CP violation beyond the Standard Model of particle physics and understanding the origin of the matter-antimatter asymmetry of the Universe. The quest for the neutron electric dipole moment started more than sixty years ago. In recent experiments, polarized ultra-cold neutrons are stored in material bottles. I will present the latest measurement to date and our new project at the Paul Scherrer Institute in Switzerland.
I will also present how we use the high sensitivity of this experiment to search for dark matter. We could set constraints on axions and also on mirror neutrons, two well motivated dark matter candidates.