Representations and derivations of quasi *-algebras induced by {\em local modifications} of states

Abstract

The relationship between the GNS representations associated to states on a quasi *-algebra, which are {\em local modifications} of each other (in a sense which we will discuss) is examined. The role of local modifications on the spatiality of the corresponding induced derivations describing the dynamics of a given quantum system with infinite degrees of freedom is discussed.

Jour. Math. Anal. Appl., in press