- Category : 1937-births
- Type : GP
- Profile : 2/4 - Hermit / Opportunist
- Definition : Split - Large
- Incarnation Cross : RAX The Four Ways 3
Norwegian mathematician who has predominantly worked within the context of operator algebras. He took his doctorate at Columbia University in 1963, and was a professor at the University of Oslo from 1974 to his retirement in 2007. He is a member of the Norwegian Academy of Science and Letters. In 2012 he became a fellow of the American Mathematical Society.