The ab initio No-Core Shell Model (NCSM) adopts an intrinsic Hamiltonian for all nucleons
in the nucleus. Realistic two-nucleon and tri-nucleon interactions are incorporated. From this
Hamiltonian, an Hermitian effective Hamiltonian is derived for a finite basis space
conserving all the symmetries of the initial Hamiltonian. The resulting finite sparse matrix
problem is solved by diagonalization on parallel computers. Applications range from light
nuclei to multiquark systems and, recently, to similar problems in quantum field theory. We …

There has been significant recent progress in solving the long-standing problems of how
nuclear shell structure and collective motion emerge from underlying microscopic inter-
nucleon interactions. We review a selection of recent significant results within the ab initio
No Core Shell Model (NCSM) closely tied to three major factors enabling this progress:(1)
improved nuclear interactions that accurately describe the experimental two-nucleon and
three-nucleon interaction data;(2) advances in algorithms to simulate the quantum many …