Most prominently, neutrons are used as a tool to study condensed matter, its magnetism, structure and dynamics. But the neutron is also a very interesting study object for fundamental physics. The properties of the neutron and its decay may help us explain the creation of the matter-antimatter symmetry in the universe, the formation of the primordial elements and more. They are a probe for beyond-Standard-Model physics and also gravity. Ultra-cold neutrons (UCN) are especially useful in this respect because of their long observation times.
The presentation will introduce UCN, their production and some of the main experiments with special focus on the upcoming ultra-cold neutron facility at TRIUMF, Vancouver.