A family of non-cocycle conjugate E_0-semigroups obtained from boundary weight doubles

TL;DR

This paper constructs a family of type II_0 E_0-semigroups from boundary weight doubles and classifies when they are cocycle conjugate, based on properties of the boundary maps and weights.

Contribution

It introduces a classification of non-cocycle conjugate E_0-semigroups derived from boundary weight doubles with rank one q-positive maps.

Findings

E_0-semigroups are non-cocycle conjugate if boundary maps have different eigenvalue lists.

Complete classification of q-corners and hyper maximal q-corners between boundary maps.

Cocycle conjugacy characterized by conjugacy of boundary maps and equality of dimensions.

Abstract

We have seen that if \phi: M_n(\C) \rightarrow M_n(\C) is a unital q-positive map and \nu is a type II Powers weight, then the boundary weight double (\phi, \nu) induces a unique (up to conjugacy) type II_0 E_0-semigroup. Let \phi: M_n(\C) \rightarrow M_n(\C) and \psi: M_{n'}(\C) \rightarrow M_{n'}(\C) be unital rank one q-positive maps, so for some states \rho \in M_n(\C)^* and \rho' \in M_{n'}(\C)^*, we have \phi(A)=\rho(A)I_n and \psi(D) = \rho'(D)I_{n'} for all A \in M_n(\C) and D \in M_{n'}(\C). We find that if \nu and \eta are arbitrary type II Powers weights, then (\phi, \nu) and (\psi, \eta) induce non-cocycle conjugate E_0-semigroups if \rho and \rho' have different eigenvalue lists. We then completely classify the q-corners and hyper maximal q-corners from \phi to \psi, obtaining the following result: If \nu is a type II Powers weight of the form \nu(\sqrt{I - \Lambda(1)} B \sqrt{I - \Lambda(1)})=(f,Bf), then the E_0-semigroups induced by (\phi,\nu) and (\psi, \nu) are cocycle conjugate if and only if n=n' and \phi and \psi are conjugate.