Precision studies of nucleonic matter and nuclei

Abstract:  Neutron stars are astrophysical objects of extremes. They contain the largest reservoirs of degenerate fermions, reaching the highest densities we can observe in the cosmos. The observed two solar mass neutron stars place important constraints on the nuclear equation of state. In August the first neutron-star merger has been observed, which provided compelling evidence that these events are an important site for the production of neutron-rich heavy elements within the r-process; these nuclei will be probed in the new FRIB facility. Present predictions for these different strongly interacting systems are limited by our understanding of nuclear interactions, and our ability to make reliable calculations. An accurate description of such systems requires precise many-body methods in combination with a systematic theory for nuclear forces. In this talk I will explain how to use chiral effective field theory (EFT) and advanced Quantum Monte Carlo (QMC) many-body methods to provide a consistent and systematic approach to strongly interacting systems and allow precision studies with controlled theoretical uncertainties. Chiral EFT is a systematic framework for strong interactions based on the symmetries of Quantum Chromodynamics. It predicts two- and many-body interactions and allows to estimate theoretical uncertainties. On the other hand, QMC methods are among the most precise many-body methods available to study strongly interacting systems at finite densities. I will present recent results for light nuclei and the nucleonic matter relevant for the nuclear astrophysics of core-collapse supernovae, neutron stars, and neutron-star mergers, and will discuss future directions and opportunities.