Certain Jordan operator algebras and double commutant theorems

Derivations of Certain Operator Algebras

Let be a nest and let be a subalgebra of L(H) containing all rank one operators of alg . We give several conditions under which any derivation δ from into L(H) must be inner. The conditions include (1) H− ≠H, (2) 0+ ≠ 0, (3) there is a nontrivial projection in which is in , and (4) δ is norm continuous. We also give some applications.

Jordan Maps on Standard Operator Algebras

Jordan isomorphisms of rings are defined by two equations. The first one is the equation of additivity while the second one concerns multiplicativity with respect to the so-called Jordan product. In this paper we present results showing that on standard operator algebras over spaces with dimension at least 2, the bijective solutions of that second equation are automatically additive.

A double commutant theorem for Murray-von Neumann algebras.

Murray-von Neumann algebras are algebras of operators affiliated with finite von Neumann algebras. In this article, we study commutativity and affiliation of self-adjoint operators (possibly unbounded). We show that a maximal abelian self-adjoint subalgebra A of the Murray-von Neumann algebra A(f)(R) associated with a finite von Neumann algebra R is the Murray-von Neumann algebra A(f)(A(0)), wh...

Derivations and Automorphisms of Certain Operator Algebras

Decomposition Theorems of Lie Operator Algebras

In this paper, we introduce a notion of Lie operator algebras which as a generalization of ordinary Lie algebras is an analogy of operator groups. We discuss some elementary properties of Lie operator algebras. Moreover, we also prove a decomposition theorem for Lie operator algebras.