English
Related papers

Related papers: C*-envelopes for operator algebras with a coaction…

200 papers

We study the structure of C*-algebras associated with compactly aligned product systems over group embeddable right LCM-semigroups. Towards this end we employ controlled maps and a controlled elimination method that associates the original…

Operator Algebras · Mathematics 2023-08-30 Evgenios T. A. Kakariadis , Elias G. Katsoulis , Marcelo Laca , Xin Li

Let $P$ be a submonoid of a group $G$ and let $\mathcal{E}=(\mathcal{E}_p)_{p\in P}$ be a product system over $P$ with coefficient C*-algebra $A$. We show that the following C*-algebras are canonically isomorphic: the C*-envelope of the…

Operator Algebras · Mathematics 2022-09-29 Camila F. Sehnem

In this exposition we highlight product systems as the semigroup analogue of Fell bundles. Motivated by Fock creation operators we extend the definition of Fowler's product systems over unital discrete left-cancellative semigroups, via both…

Operator Algebras · Mathematics 2021-11-29 Evgenios T. A. Kakariadis

Let $(G, P)$ be an abelian, lattice ordered group and let $X$ be a compactly aligned product system over $P$. We show that the C*-envelope of the Nica tensor algebra $\mathcal{N}\mathcal{T}^+_X$ coincides with both Sehnem's covariance…

Operator Algebras · Mathematics 2019-11-27 Adam Dor-On , Elias Katsoulis

In this paper, we construct, for a certain class of semigroup dynamical systems, two operator algebras that are universal with respect to their corresponding covariance conditions: one being self-adjoint, and another being non-self-adjoint.…

Operator Algebras · Mathematics 2020-07-10 Boyu Li

Let X be a product system over a quasi-lattice ordered group. Under mild hypotheses, we associate to X a C*-algebra which is co-universal for injective Nica covariant Toeplitz representations of X which preserve the gauge coaction. Under…

Operator Algebras · Mathematics 2012-03-09 Toke Meier Carlsen , Nadia S. Larsen , Aidan Sims , Sean Vittadello

The C*-envelope of a non self-adjoint operator algebra is known to encode many properties of the underlying subalgebra. However, the C*-envelope does not always encode the residual finite-dimensionality of an operator algebra. To elucidate…

Operator Algebras · Mathematics 2025-07-17 Adam Humeniuk , Christopher Ramsey , Ian Thompson

We give a new very concrete description of the C*-envelope of the tensor algebra associated to multivariable dynamical system. In the surjective case, this C*-envelope is described as a crossed product by an endomorphism, and as a groupoid…

Operator Algebras · Mathematics 2008-12-02 K. R. Davidson , J. Roydor

In this paper we study the C*-envelope of the (non-self-adjoint) tensor algebra associated via subproduct systems to a finite irreducible stochastic matrix $P$. Firstly, we identify the boundary representations of the tensor algebra inside…

Operator Algebras · Mathematics 2016-10-05 Adam Dor-On , Daniel Markiewicz

We examine the semicrossed products of a semigroup action by $*$-endomorphisms on a C*-algebra, or more generally of an action on an arbitrary operator algebra by completely contractive endomorphisms. The choice of allowable representations…

Operator Algebras · Mathematics 2018-08-17 Kenneth R. Davidson , Adam H. Fuller , Evgenios T. A. Kakariadis

Let $\mathcal{C}$ be a C*-algebra and $\alpha:\mathcal{C} \rightarrow \mathcal{C}$ a unital *-endomorphism. There is a natural way to construct operator algebras which are called semicrossed products, using a convolution induced by the…

Operator Algebras · Mathematics 2018-08-17 Evgenios T. A. Kakariadis

Let $P$ be a unital subsemigroup of a group $G$. We propose an approach to $\mathrm{C}^*$-algebras associated to product systems over $P$. We call the $\mathrm{C}^*$-algebra of a given product system $\mathcal{E}$ its covariance algebra and…

Operator Algebras · Mathematics 2018-11-21 Camila F. Sehnem

Let $\sS$ be a countable, abelian semigroup of continuous surjections on a compact metric space $X$. Corresponding to this dynamical system we associate two operator algebras, the tensor algebra, and the semicrossed product. There is a…

Operator Algebras · Mathematics 2014-10-07 Benton L. Duncan , Justin R. Peters

We establish the dual equivalence of the category of (potentially nonunital) operator systems and the category of pointed compact nc (noncommutative) convex sets, extending a result of Davidson and the first author. We then apply this dual…

Operator Algebras · Mathematics 2021-03-24 Matthew Kennedy , Se-Jin Kim , Nicholas Manor

Given a unital $\boldsymbol{C}^{*}$-algebra $\mathcal{A}$, we prove the existence of the coproduct of two faithful operator $\mathcal{A}$-systems. We show that we can either consider it as a subsystem of an amalgamated free product of…

Operator Algebras · Mathematics 2025-04-25 Alexandros Chatzinikolaou

We study operator algebras arising from monomial ideals in the ring of polynomials in noncommuting variables, through the apparatus of subproduct systems and C*-correspondences. We provide a full comparison amongst the related operator…

Operator Algebras · Mathematics 2020-01-24 Evgenios T. A. Kakariadis , Orr M. Shalit

C*-algebras are rings, sometimes nonunital, obeying certain axioms that ensure a very well-behaved representation theory upon Hilbert space. Moreover, there are some well-known features of the representation theory leading to subtle…

Operator Algebras · Mathematics 2023-07-07 Cristian Ivanescu , Dan Kucerovsky

The universal C*-algebras of discrete product systems generalize the Toeplitz- Cuntz algebras and the Toeplitz algebras of discrete semigroups. We consider a semigroup P which is quasi-lattice ordered in the sense of Nica, and, for a…

Operator Algebras · Mathematics 2007-05-23 Neal J. Fowler

Let E be a row-finite directed graph. We prove that there exists a C*-algebra C*_{min}(E) with the following co-universal property: given any C*-algebra B generated by a Toeplitz-Cuntz-Krieger E-family in which all the vertex projections…

Operator Algebras · Mathematics 2008-09-16 Aidan Sims

We show that a normal coaction of a discrete group on an operator algebra extends to a normal coaction on the C*-envelope. This resolves an open problem attempted by several experts in the area, and provides a more direct proof of a…

Operator Algebras · Mathematics 2026-04-06 Kevin Aguyar Brix , Chris Bruce , Adam Dor-On
‹ Prev 1 2 3 10 Next ›