Nuclear Saturation with Low Momentum Interactions

Relativistic effects are investigated in nuclear matter calculations employing renormalized low-momentum nucleon-nucleon ($NN$) interactions. It is demonstrated that the relativistic effects cure a problem of non-relativistic low-momentum interactions, which fail to reproduce saturation of nuclear matter. Including relativistic effects, one already obtains saturation in a Hartree-Fock calculation. Brueckner-Hartree-Fock calculations lead to a further improvement of the saturation properties. The results are rather insensitive to the realistic $NN$ interaction on which they are based.