  Using numerically exact methods we examine the Fermi-Hubbard model on
arbitrary cluster topology. We focus on the question which systems eventually
equilibrate or even thermalize after an interaction quench when initially
prepared in a state highly entangled between system and bath. We find that
constants of motion in integrable clusters prevent equilibration to the thermal
state. We discuss the size of fluctuations during equilibration and
thermalization and the influence of integrability. The influence of real space
topology and in particular of infinite-range graphs on equilibration and
thermalization is studied.
