Sequential isomorphisms between the sets of von Neumann algebra effects

In this paper we describe the structure of all sequential isomorphisms between the sets of von Neumann algebra effects. It turns out that if the underlying algebras have no commutative direct summands, then every sequential isomorphism between the sets of their effects extends to the direct sum of a *-isomorphism and a *-antiisomorphism between the underlying von Neumann algebras.Comment: To appear in Acta Sci. Math. (Szeged

On isomorphisms of standard operator algebras

The aim of this paper is to show that between standard operator algebras every bijective map with a certain multiplicativity property related to Jordan triple isomorphisms of associative rings is automatically additive.Comment: 8 pages. To appear in Studia Mat