NONUNIMODULAR RING GROUPS AND HOPF-VON NEUMANN ALGEBRAS

A number of authors have introduced ring groups as objects generalizing locally compact groups. An analogue of the Pontrjagin principle of duality holds for ring groups. In this paper we introduce a wider class of ring groups, one including the locally compact groups.A construction is given whereby to each ring group there is defined a dual ring group ; here . By definition a ring group is determined by a -algebra (the space of the ring group) equipped with an additional structure which allows to be considered, in particular, as a Hopf-von Neumann algebra. When is a locally compact group, is the -algebra of bounded measurable functions on , considered in the natural way as operators in .Bibliography: 15 items.