Monte Carlo calculations of fermionic systems with local two-body potentials

Monte Carlo calculations in the canonical ensemble of fermionic models consisting of kinetic energy and local two-body interactions are discussed. In two space dimensions the author considered an attractive exponential and a repulsive square well. Also Hamiltonians having pairing properties are discussed. It is shown that the sampling of the partition function with one-body potentials with a Gaussian probability density around the mean field gives values for energy which agree with the corresponding quantities obtained with the importance sampling method