The haagerup problem on subadditive weights on W *-algebras

Abstract

In 1975 U. Haagerup stated the following question: Is every normal subadditive weight on a W *-algebra sigma-weakly lower semicontinuous? Here we positively answer this question in a particular case of abelian W *-algebras and present a general form of normal subadditive weights on these algebras. © Allerton Press, Inc., 2011.