Quantum Monte Carlo for Nuclear Structure and Reactions

Nuclear Lattice Effective Field Theory (NLEFT) has emerged as a powerful framework for ab-initio calculations of nuclear structure and reaction observables. In NLEFT, nuclear forces derived from chiral EFT are formulated on a periodic cubic lattice, and many-body amplitudes are evaluated with stochastic algorithms, including auxiliary-field Monte Carlo, impurity Monte Carlo, and perturbative Monte Carlo methods. I will outline how these methods are used for both bound and scattering problems, emphasizing their crucial role in bridging the gap between quantum chromodynamics (QCD) and low-energy nuclear phenomena, as well as strategies for sign-problem mitigation. Additionally, I will discuss recent developments, including a novel method called wavefunction matching, and present state-of-the-art ab initio calculations for systems involving hyperons.