Author : Alessandro Giuliani
Title: Ground state energy of the low density Hubbard model: An upper bound
Abstract: We derive an upper bound on the ground state energy of the three-dimensional (3D) repulsive Hubbard model on the cubic lattice agreeing in the low density limit with the known asymptotic expression of the ground state energy of the dilute Fermi gas in the continuum. As a corollary, we prove an old conjecture on the low density behavior of the 3D Hubbard model, i.e., that the total spin of the ground state vanishes as the density goes to zero.
Keywords: Hubbard model; ground state energy; upper bound; low density limit.
Department of Physics, Princeton University, Princeton 08544 NJ, USA