Crossed products of Banach algebras. III
Abstract
In earlier work a crossed product of a Banach algebra was constructed from a Banach algebra dynamical system (A,G,α) and a class R of continuous covariant representations, and its representations were determined. In this paper we adapt the theory to the ordered context. We construct a pre-ordered crossed product of a Banach algebra from a pre-ordered Banach algebra dynamical system (A,G,α) and a given uniformly bounded class R of continuous covariant representations of (A,G,α). If A has a positive bounded approximate left identity and R consists of non-degenerate continuous covariant representations, we establish a bijection between the positive non-degenerate bounded representations of the pre-ordered crossed product on pre-ordered Banach spaces with closed cones and the positive non-degenerate R-continuous covariant representations of (A,G,α) on such spaces. Under mild conditions, we show that this pre-ordered crossed product is the essentially unique pre-ordered Banach algebra for which such a bijection exists. Finally, we study pre-ordered generalized Beurling algebras. We show that they are bipositively topologically isomorphic to pre-ordered crossed products of Banach algebras associated with pre-ordered Banach algebra dynamical systems, and hence the general theory allows us to describe their positive representations on pre-ordered Banach spaces with closed cones.