A priori estimates for symmetrizing measures and their applications to Gibbs states

We prove existence and uniform a priori estimates for tempered Gibbs states of certain classical lattice systems with unbounded spins, nonharmonic pai l potentials, and infinite radius of interaction. We use all alternative ch aracterization of Gibbs measures in terms of their Radon-Nikodym derivative s w.r.t. local shifts of the configuration space and corresponding integrat ion by parts formulas. (C) 2000 Academic Press.