Decompositions of Beurling Type for E_0-Semigroups
arXiv:math/0412107
Abstract
We define tensor product decompositions of -semigroups with a structure analogous to a classical theorem of Beurling. Such decompositions can be characterized by adaptedness and exactness of unitary cocycles. For CCR-flows we show that such cocycles are convergent.
minor corrections, 10 pages