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Related papers: E-semigroups over closed convex cones

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We investigate $E_0-$semigroups on general factors, which are not necessarily of type I, and analyse associated invariants like product systems, super product systems etc. By tensoring $E_0-$semigroups on type I factors with…

Operator Algebras · Mathematics 2014-09-26 Oliver T. Margetts , R. Srinivasan

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

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

Let $P$ be a closed convex cone in $\mathbb{R}^{d}$ which we assume to be spanning and pointed i.e. $P-P=\mathbb{R}^{d}$ and $P \cap -P=\{0\}$. In this article, we consider CCR flows over $P$ associated to isometric representations that…

Operator Algebras · Mathematics 2019-07-12 Anbu Arjunan , S. Sundar

Recently it is proved in arXiv:1906.05493v1 [math.OA] that CCR flows over convex cones are cocycle conjugate if and only if the associated isometric representations are conjugate. We provide a very short, simple and direct proof of that.…

Operator Algebras · Mathematics 2019-08-02 R. Srinivasan

Given any directed graph E one can construct a graph inverse semigroup G(E), where, roughly speaking, elements correspond to paths in the graph. In this paper we study the semigroup-theoretic structure of G(E). Specifically, we describe the…

Group Theory · Mathematics 2016-07-27 Zachary Mesyan , J. D. Mitchell

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 revisit Arveson's characterisation of CCR flows in terms of decomposibility of the product system in the multiparameter context. We show that a multiparameter $E_0$-semigroup is a CCR flow if and only if it is decomposable…

Operator Algebras · Mathematics 2019-12-03 S. Sundar

We describe the structure of 0-simple countably compact topological inverse semigroups and the structure of congruence-free countably compact topological inverse semigroups.

Group Theory · Mathematics 2008-04-10 Oleg Gutik , Dušan Repovš

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 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

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

Let $P$ be a pointed, closed convex cone in $\mathbb{R}^d$. We prove that for two pure isometric representations $V^{(1)}$ and $V^{(2)}$ of $P$, the associated CAR flows $\beta^{V^{(1)}}$ and $\beta^{V^{(2)}}$ are cocycle conjugate if and…

Operator Algebras · Mathematics 2023-12-12 C. H. Namitha , S. Sundar

An E_0-semigroup is called q-pure if it is a CP-flow and its set of flow subordinates is totally ordered by subordination. The range rank of a positive boundary weight map is the dimension of the range of its dual map. Let K be a separable…

Operator Algebras · Mathematics 2011-06-14 Christopher Jankowski , Daniel Markiewicz , Robert T. Powers

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

In the paper we study the semigroup $\mathscr{C}_{\mathbb{Z}}$ which is a generalization of the bicyclic semigroup. We describe main algebraic properties of the semigroup $\mathscr{C}_{\mathbb{Z}}$ and prove that every non-trivial…

Group Theory · Mathematics 2012-01-04 Iryna Fihel , Oleg Gutik

We introduce so-called cone topologies of paratopological groups, which are a wide way to construct counterexamples, especially of examples of compact-like paratopological groups with discontinuous inversion. We found a simple interplay…

Group Theory · Mathematics 2019-08-08 Alex Ravsky

Let $P$ be a closed convex cone in $\mathbb{R}^{n}$. Assume that $P$ is spanning i.e. $P-P=\mathbb{R}^{n}$ and pointed i.e. $P \cap -P=\{0\}$. Let $\alpha:=\{\alpha_{x}:x \in P\}$ be a $\sigma$-weakly continuous family of unital normal…

Operator Algebras · Mathematics 2017-06-14 S. P. Murugan , S. Sundar

The cone of lower semicontinuous traces is studied with a view to its use as an invariant. Its properties include compactness, Hausdorffness, and continuity with respect to inductive limits. A suitable notion of dual cone is given. The cone…

Operator Algebras · Mathematics 2009-01-21 George A. Elliott , Leonel Robert , Luis Santiago

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
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