Many nuclear processes in our universe occur under extreme conditions in supernovae and neutron stars. The properties of nuclei and nuclear matter under these conditions, which are difficult or impossible to reproduce in the laboratory, must necessarily be calculated theoretically. These data are needed to understand astrophysically important systems and processes such as neutron rich matter, neutron stars, supernovae, and r-process nucleosynthesis and neutrino scattering. The quantum many-particle methods developed within this project have broad applications across many areas of physics. These include the nuclear physics aspects directly relating to the project, cold atomic gas research, and electronic structure. Methods previously developed within this project have been applied in each of these areas. The project will train both undergraduate and graduate students, give them exposure at national and international conferences, and provide for dissemination of the results.
This project will continue work developing and using accurate techniques to calculate the properties of nuclei and nuclear matter using quantum Monte Carlo methods, i.e. stochastic sampling methods for the large number of quantum degrees of freedom. A primary aim is to develop auxiliary field quantum Monte Carlo methods to sample both the space and spin-isospin degrees of freedom of protons and neutrons in nuclei with all important parts of the nuclear interaction. These include both the spin-orbit and three-body interactions. New wave functions which can be efficiently evaluated for nuclei are being developed, with the goal of obtaining accurate properties for medium to large and neutron rich nuclei. Superfluidity has major consequences in neutron star matter. The investigator and his students will use the same methods to study both the nuclear systems and the related phenomena in cold atomic gases. Many of the pairing and superfluid mechanisms important in nuclei and nuclear matter can be studied and verified in these systems where detailed experimental measurements can be made using table-top experimental setups.
