Quantum Structures Versus Partially Ordered Groups

Abstract

We present a survey of applications of partially ordered groups (= po-groups) in quantum structures. The survey has two levels: (1) To show when an effect algebra or a pseudo effect algebra is an interval in the positive cone of a po-group. A sufficient condition is a kind of the Riesz Decomposition Property, i.e. a property when two decompositions have a joint refinement. (2) Using an arbitrary power of the positive and negative cone of a po-group and two injections, we can construct a large class of pseudo effect algebras which are called kite pseudo effect algebras, and we describe basic properties of this class.