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Related papers: Non-cocycle-conjugate $E_0$-semigroups on factors

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We introduce four new cocycle conjugacy invariants for E_0-semigroups on II_1 factors: a coupling index, a dimension for the gauge group, a super product system and a C*-semiflow. Using noncommutative It\^o integrals we show that the…

Operator Algebras · Mathematics 2015-06-11 Oliver T. Margetts , R. Srinivasan

In this paper we study modular extendability and equimodularity of endomorphisms and E$_0$-semigroups on factors with respect to f.n.s. weights. We show that modular extendability is a property that does not depend on the choice of weights,…

Operator Algebras · Mathematics 2014-10-27 Panchugopal Bikram , Daniel Markiewicz

We initiate a study of E-semigroups over convex cones. We prove a structure theorem for E-semigroups which leave the algebra of compact operators invariant. Then we study in detail the CCR flows, E$_0$semigroups constructed from isometric…

Operator Algebras · Mathematics 2018-07-31 Anbu Arjunan , R. Srinivasan , S. Sundar

W. Arveson has described a cocycle conjugacy class $U(\alpha)$ of $E_0$-semigroup $\alpha$ on B(H) which is a factor of type $\rm I$. Under some conditions on $\alpha$, there is a $E_0$-semigroup $\beta \in U(\alpha)$ being a flow of shifts…

Operator Algebras · Mathematics 2007-05-23 G. G. Amosov

We introduce a new construction of $E_0$-semigroups, called generalized CCR flows, with two kinds of descriptions: those arising from sum systems and those arising from pairs of $C_0$-semigroups. We get a new necessary and sufficient…

Operator Algebras · Mathematics 2009-11-13 Masaki Izumi , R. Srinivasan

We introduce a cohomology theory for spatial super- product systems and compute the $2-$cocycles for some basic examples called as Clifford super-product systems, thereby distinguish them up to isomorphism. This consequently proves that a…

Operator Algebras · Mathematics 2019-07-17 Oliver T. Margetts , R Srinivasan

The gauge group is computed explicitly for a family of E_0-semigroups of type II_0 arising from the boundary weight double construction introduced earlier by Jankowski. This family contains many E_0-semigroups which are not cocycle cocycle…

Operator Algebras · Mathematics 2011-03-01 Christopher Jankowski , Daniel Markiewicz

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)…

Operator Algebras · Mathematics 2010-07-27 Christopher Jankowski

Product systems are the classifying structures for semigroups of endomorphisms of B(H), in that two $E_0$-semigroups are cocycle conjugate iff their product systems are isomorphic. Thus it is important to know that every abstract product…

Operator Algebras · Mathematics 2007-05-23 William Arveson

Let B be a sigma-unital C*-algebra. We show that every strongly continuous E_0-semigroup on the algebra of adjointable operators on a full Hilbert B-module E gives rise to a full continuous product system of correspondences over B. We show…

Operator Algebras · Mathematics 2013-11-20 Michael Skeide

We consider families of E_0-semigroups continuously parametrized by a compact Hausdorff space, which are cocycle-equivalent to a given E_0-semigroup \beta. When the gauge group of $\beta$ is a Lie group, we establish a correspondence…

Operator Algebras · Mathematics 2011-06-30 Ilan Hirshberg , Daniel Markiewicz

This paper presents the complete classification of E_0-semigroups by product systems in the case of von Neumann correspondences, and under countability assumptions in the case of C*-correspondences.

Operator Algebras · Mathematics 2016-07-29 Michael Skeide

The subordinate E-semigroups of a fixed E-semigroup are in one-to-one correspondence with local projection-valued cocycles of that semigroup. For the CCR flow we characterise these cocycles in terms of their stochastic generators, that is,…

Operator Algebras · Mathematics 2010-11-16 Stephen J. Wills

We construct numerous continuous families of irreducible subfactors of the hyperfinite II$_1$ factor, which are non-isomorphic, but have all the same standard invariant. In particular, we obtain 1-parameter families of irreducible,…

Operator Algebras · Mathematics 2007-05-23 Dietmar Bisch , Remus Nicoara , Sorin Popa

We define tensor product decompositions of $E_0$-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…

Operator Algebras · Mathematics 2009-02-26 Rolf Gohm

These lectures concern basic aspects of the theory of semigroups of endomorphisms of type $I$ factors that relate to causal dynamics, dilation theory, and the problem of classifying $E_0$-semigroups up to cocycle conjugacy. We give only a…

Operator Algebras · Mathematics 2007-05-23 William Arveson

We analyze Fourier hyperfunction and hyperfunction semigroups with non-densely defined generators and their connections with local convoluted $C$-semigroups. Structural theorems and spectral characterizations give necessary and sufficient…

Functional Analysis · Mathematics 2014-02-04 Marko Kostić , Stevan Pilipović , Daniel Velinov

A CP-semigroup is aligned if its set of trivially maximal subordinates is totally ordered by subordination. We prove that aligned spatial E_0-semigroups are prime: they have no non-trivial tensor product decompositions up to cocycle…

Operator Algebras · Mathematics 2011-07-12 Christopher Jankowski , Daniel Markiewicz , Robert T. Powers

Coclass theory has been a highly successful approach towards the investigation and classification of finite nilpotent groups. Here we suggest a similar approach for finite nilpotent semigroups. This differs from the group theory setting in…

Rings and Algebras · Mathematics 2014-04-17 Andreas Distler , Bettina Eick

We consider $\text{\rm II}_1$ factors $L_\mu(G)$ arising from 2-cocyles $\mu \in \text{\rm H}^2(G,\Bbb T)$ on groups $G$ containing infinite normal subgroups $H \subset G$ with the relative property $\text{\rm(T)}$ (i.e. $G$ {\it w-rigid}).…

Operator Algebras · Mathematics 2007-05-23 Remus Nicoara , Sorin Popa , Roman Sasyk
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