  Ground state properties of the repulsive Hubbard model on a cubic lattice are
investigated by means of the auxiliary-field quantum Monte Carlo method. We
focus on low-density systems with varying on-site interaction $U/t$, as a model
relevant to recent experiments on itinerant ferromagnetism in a dilute Fermi
gas with contact interaction. Twist-average boundary conditions are used to
eliminate open-shell effects and large lattice sizes are studied to reduce
finite-size effects. The sign problem is controlled by a generalized
constrained path approximation. We find no ferromagnetic phase transition in
this model. The ground-state correlations are consistent with those of a
paramagnetic Fermi liquid.
