Diagrammatic ab initio methods for infinite nuclear matter with modern chiral interactions

A realistic description of the equation of state of nuclear matter is of paramount importance for understanding neutron-star structure and astrophysical phenomena. The authors perform benchmark a00exb i00exn00exi00ext00exi00exo calculations for nuclear matter with several modern chiral interactions using three diagrammatic methods: coupled-cluster theory, self-consistent Green's functions, and many-body perturbation theory. They obtain robust predictions for the equation of state of both pure neutron matter and symmetric nuclear matter, especially for soft chiral potentials. The very good agreement between different techniques, in particular between the nonperturbative coupled-cluster and Green's functions methods, suggests that these many-body approaches can reach high accuracy, and uncertainties on the equation of state are mostly related to the nuclear interaction.