Massless quantum sine–Gordon equation in two space–time dimensions: Correlation inequalities and infinite volume limit

Abstract

We prove new correlation inequalities for the massive and massless quantum sine–Gordon equations. These results are then used to construct infinite volume limit theory for the massless (S–G)₂ model that satisfies the Osterwalder–Schrader axioms. As consequences, infinite volume limit theories for the classical, neutral, statistical mechanical systems with two‐body Coulomb potentials and for the massive Thirring model exist.