This article was published
Thursday Jan 24, 2013
Spectral moment sum rules for the retarded Green's function and self-energy of the inhomogeneous Bose-Hubbard model in equilibrium and nonequilibrium
J. K. Freericks, V. Turkowski, H. R. Krishnamurthy, and M. Knap
Phys. Rev. A 87, 013628 (2013)