The First Steps in the Chemical Evolution
Prof. Michael Wiescher
Freimann Professor of Physics
University of Notre Dame
The understanding of the chemical evolution of our universe is one of the key topics in the field of nuclear astrophysics. This talk concentrates on the discussion of the very first steps in this process, the conversion of the primordial particle of protons and neutrons to helium and further to the biological elements of carbon and oxygen. This question is not only linked to the first emergence of heavier elements in the early universe, but also to the question of the rapid build-up of heavier elements in other expanding environments such as the emergence of the neutrino driven supernova shock and the expansion of neutron star mergers. The transition from primordial to biological elements in the carbon, oxygen range and beyond depends critically on the cluster nature of nuclei. The talk will focus on this aspect of chemical evolution and will present the experimental evidence for this claim.