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Related papers: A Bivariant Theory for the Cuntz Semigroup

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We define the filtrated K-theory of a C*-algebra over a finite topological space X and explain how to construct a spectral sequence that computes the bivariant Kasparov theory over X in terms of filtrated K-theory. For finite spaces with…

Operator Algebras · Mathematics 2015-10-23 Ralf Meyer , Ryszard Nest

The (abstract) Cuntz algebra is generated by non-unitary isometries and has therefore no intrinsic finiteness properties. To approximate the elements of the Cuntz algebra by finite-dimensional objects, we thus consider a spatial…

Operator Algebras · Mathematics 2008-11-20 Steffen Roch

In this paper we generalize the notion of Cuntz-Pimsner algebras of $C^*$-correspondences to the setting of subproduct systems. The construction is justified in several ways, including the Morita equivalence of the operator algebras under…

Operator Algebras · Mathematics 2012-07-18 Ami Viselter

We define possibly unsaturated, upper semicontinuous Fell bundles over Hausdorff, locally compact groupoids and establish a universal property for representations of their full section C*-algebras on Hilbert modules over arbitrary…

Operator Algebras · Mathematics 2026-04-07 Alcides Buss , Rohit Holkar , Ralf Meyer

We observe almost divisibility for the original Cuntz semigroup of a simple AH algebra with strict comparison. As a consequence, the properties of strict comparison, finite nuclear dimension, and Z-stability are equivalent for such…

Operator Algebras · Mathematics 2011-02-07 Andrew S. Toms

We augment Restorff's classification of purely infinite Cuntz-Krieger algebras by describing the range of his invariant on purely infinite Cuntz-Krieger algebras. We also describe its range on purely infinite graph C*-algebras with finitely…

Operator Algebras · Mathematics 2014-03-17 Sara E. Arklint , Rasmus Bentmann , Takeshi Katsura

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

We introduce the notion of continuous orbit equivalence for partial dynamical systems, and give an equivalent characterization in terms of Cartan-isomorphisms for partial C*-crossed products. Both graph C*-algebras and semigroup C*-algebras…

Operator Algebras · Mathematics 2016-03-31 Xin Li

In this note we show that a combinatorial model of Kirchberg algebras in the UCT, namely the Katsura algebras O_{AB}, can be expressed both as groupoid C*-algebras and as inverse semigroup crossed products. We use this picture to obtain…

Operator Algebras · Mathematics 2013-04-24 Ruy Exel , Enrique Pardo

We present a short proof of the gauge invariant uniqueness theorem for relative Cuntz-Pimsner algebras of C*-correspondences.

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

We study semigroup C*-algebras of semigroups associated with number fields and initial data arising naturally from class field theory. Using K-theoretic invariants, we investigate how much information about the initial number-theoretic data…

Operator Algebras · Mathematics 2024-01-25 Chris Bruce , Xin Li

Let $X$ be a product system over a quasi-lattice ordered groupoid $(G,P)$. Under mild hypotheses, we associate to $X$ a $C^*$-algebra which is couniversal for injective Nica covariant Toeplitz representations of $X$ which preserve the gauge…

Operator Algebras · Mathematics 2024-01-10 Massoud Amini , Mahdi Moosazadeh

Let $A$ be a unital simple separable exact C$^*$-algebra which is approximately divisible and of real rank zero. We prove that the set of positive elements in $A$ with a fixed non-compact Cuntz class has vanishing homotopy groups. Combined…

Operator Algebras · Mathematics 2022-10-27 Andrew S. Toms

In this paper we give a formula for the $K$-theory of the $C^*$-algebra of a weakly left-resolving labelled space. This is done by realising the $C^*$-algebra of a weakly left-resolving labelled space as the Cuntz-Pimsner algebra of a…

Operator Algebras · Mathematics 2017-05-10 Teresa Bates , Toke Meier Carlsen , David Pask

This survey article on relative homological algebra in bivariant K-thoery is mainly intended for readers with a background knowledge in triangulated categories. We briefly recall the general theory of relative homological algebra in…

Operator Algebras · Mathematics 2023-03-03 George Nadareishvili

We characterise stable finiteness and pure infiniteness of the essential crossed product of a C*-algebra by an action of an inverse semigroup. Under additional assumptions, we prove a stably finite / purely infinite dichotomy. Our main…

Operator Algebras · Mathematics 2026-01-13 Becky Armstrong , Lisa Orloff Clark , Astrid An Huef , Diego Martínez , Ilija Tolich

An overview about C*-algebra bundles with a Z-grading is presented, with particular emphasis on classification questions. In particular, we discuss the role of the representable KK(X ; -, -)-bifunctor introduced by Kasparov. As an…

K-Theory and Homology · Mathematics 2011-11-21 Ezio Vasselli

In an earlier paper, the authors introduced partial translation algebras as a generalisation of group C*-algebras. Here we establish an extension of partial translation algebras, which may be viewed as an excision theorem in this context.…

Operator Algebras · Mathematics 2013-04-29 Jacek Brodzki , Graham A. Niblo , Nick Wright

We generalize the Li-Yang notion of self-similar $k$-graph $(G,\Lambda)$ and its $C^*$-algebra $\mathcal{O}_{G,\Lambda}$ to any finitely aligned $k$-graph $\Lambda$. We then introduce an inverse semigroup model for $\mathcal{O}_{G,\Lambda}$…

Operator Algebras · Mathematics 2024-11-22 Hossein Larki

We prove that the Cuntz-Pimsner algebra O(E) of a vector bundle E over a compact metrizable space X is determined up to an isomorphism of C(X)-algebras by the ideal (1-[E])K(X) of the K-theory ring K(X). Moreover, if E and F are vector…

Operator Algebras · Mathematics 2010-04-27 Marius Dadarlat