On the uniqueness of invariant states

Abstract

Given an abelian group G endowed with a T=R/Z-pre-symplectic form, we assign to it a symplectic twisted group ⁎-algebra WG and then we provide criteria for the uniqueness of states invariant under the ergodic action of the symplectic group of automorphism. As an application, we discuss the notion of natural states in quantum abelian Chern-Simons theory.