Talk 24.06.2019

Speaker:David Marsh
Institute for Astrophysics, University of Göttingen


Title: Axions: the lightest place in the dark

Abstract:
85% of the matter in the Universe is missing. There are many theories for what this missing "dark matter" could be. One of the leading theories is that it is a new type of particle called an "axion". Of all the possibilities for dark matter particles, the axion is the lightest, with each particle possibly being as light as 10^-58 kg (that's 10^31 times lighter than the proton!). There are many ways to search for axions in their effects on astrophysical observables, including the cosmic microwave background anistropies, high redshift galaxy formation, the orbits of stars in Milky Way satellites, and the spins of black holes. On Earth, they could show up causing anomalous spin precession of neutrons, or interacting with magnons inside topological insulators. Huge progress is being made in efforts to detect axions, particularly here in Germany. The solution to the mystery of dark matter could be just around the corner."