Aligned CP-Semigroups
Christopher Jankowski, Daniel Markiewicz, Robert T. Powers · International Mathematics Research Notices · 2014
A CP-semigroup is aligned if its set of trivially maximal subordinates is totally ordered by subordination. We prove that aligned spatial E0-semigroups are prime: they have no nontrivial tensor product decompositions up to cocycle conjugacy. As a consequence, we establish the existence of uncountably many noncocycle conjugate E0-semigroups of type II0 which are prime.