Low-momentum interactions for nuclei

We show how the renormalization group is used to construct a low-momentum nucleon-nucleon interaction V-low k, Which unifies all potential models used in nuclear structure calculations. V-low k can be directly applied to the nuclear shell model or to nucleonic matter without a G matrix resummation. It is argued that V-low k parametrizes a high-order chiral effective field theory two-nucleon force. We use cutoff dependence as a tool to assess the error in the truncation of nuclear forces to two-nucleon interactions and introduce a low-momentum three-nucleon force, which-regulates A = 31 4 binding energies. The adjusted three-nucleon interaction is perturbative for small cutoffs. In contrast to other precision interactions, the error due to missing many-body forces can be estimated, when V-low k and the corresponding three-nucleon force a re used in nuclear structure calculations and the cutoff is varied.