Lattice theory for low energy fermions at nonzero chemical potential

We construct a lattice theory describing a system of interacting nonrelativistic spin s=1/2fermions at nonzero chemical potential. The theory is applicable whenever the interparticle separation is large compared to the range of the two-body potential and does not suffer from a sign problem. In particular, the theory could be useful in studying the thermodynamic limit of fermion systems for which the scattering length is much larger than the interparticle spacing, with applications to realistic atomic systems and dilute neutron gases.