Coarse graining nuclear interactions

We consider a coarse graining of NN interactions in coordinate space very much in the spirit of the well known Vlowk approach. To this end we sample the interaction at about the minimal de Broglie wavelength probed by NN scattering below the pion production threshold. This amounts to providing a simple delta-shell potential plus the standard OPE potential above 2 fm. The possible simplifications in the nuclear many body problem are discussed.