The strong nuclear interaction: governing the quantum properties of nuclei and the neutron-star equation of state

Research Project, 2021 – 2024

The aim of this project is to use chiral effective field theory (χEFT), ab initio many-body theory, and Bayesian inference methods to quantify the theoretical uncertainties in the prediction of the neutron-skin thickness of 208-Pb and the density-dependent parameters of the nuclear equation of state (EOS) up to nuclear saturation densities. The result is a ground-breaking ab initio quantification of the correlation pattern between the skin-thickness in 208-Pb and the slope parameter of the symmetry energy.This will provide a fundamental interpretation of upcoming PREX and MREX measurements of the neutron skin in 208-Pban important test to validate our knowledge about the strong nuclear interaction according to effective field theorya link between sub-saturation EOS properties and data from finite nucleinew scientific questions about neutron stars and the mechanism that stabilizes very neutron-rich nucleiThe breakthrough that permits this project to succeed is a new method called subspace-projected coupled cluster (SPCC) [A. Ekström et al., PRL, 123, 252501, 2019]. With SPCC, I expect to enable high-precision ab initio predictions of 208-Pb and the nuclear EOS for more than a million values of the low-energy constants in the χEFT description of the nuclear interaction, all in one hour on a standard laptop. The dramatic reduction of the computational cost that SPCC offers (speedup : >105) finally enables robust Bayesian inference analyses in ab initio nuclear theory.