Axion Dark Matter
Priv. Doz. Dr. Georg Raffelt (MPI f. Physik, München)
The physical nature of the cosmic dark matter remains perhaps the most vexing mystery of contemporary cosmology. One well-motivated particle-physics solution is provided by the hypothesis of axions, very weakly interacting and very low-mass particles, that would simultaneously explain why quantum-chromodynamics perfectly
respects the symmetry between matter and anti-matter ("strong CP problem"). The theoretical motivation for axions, their cosmological role, experimental searches, and astrophysical limits will be explained and reviewed.