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Related papers: K-theory for generalized Lamplighter groups

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We introduce controlled $KK$-theory groups associated to a pair $(A,B)$ of separable $C^*$-algebras. Roughly, these consist of elements of the usual $K$-theory group $K_0(B)$ that approximately commute with elements of $A$. Our main results…

Operator Algebras · Mathematics 2024-08-27 Rufus Willett , Guoliang Yu

Spielberg's construction of C*-algebras from left cancellative small categories is a common generalization for most C*-algebras one would consider to come from ``combinatorial data,'' including graph and $k$-graph C*-algebras, Li's…

Operator Algebras · Mathematics 2026-05-14 Charles Starling

We show that unital simple C*-algebras with tracial topological rank zero which are locally approximated by subhomogeneous C^-algebras can be classified by their ordered $K$-theory. We apply this classification result to show that certain…

Operator Algebras · Mathematics 2007-05-23 Huaxin Lin

Categories of paths are a generalization of several kinds of oriented discrete data that have been used to construct $C^*$-algebras. The techniques introduced to study these constructions apply almost verbatim to the more general situation…

Operator Algebras · Mathematics 2018-06-13 Jack Spielberg

In this paper we show that the universal C*-algebra satisfying the Cuntz-Li relations is generated by an inverse semigroup of partial isometries. We apply Exel's theory of tight representations to this inverse semigroup. We identify the…

Operator Algebras · Mathematics 2012-04-02 S. Sundar

We discuss a very general Kirillov Theory for the representations of certain nilpotent groups which gives a combined view an many known examples from the literature.

Representation Theory · Mathematics 2011-07-28 Siegfried Echterhoff , Helma Klüver

We prove that all eight KO groups for a real C*-algebra can be constructed from homotopy classes of unitary matrices that respect a variety of symmetries. In this manifestation of the KO groups, all eight boundary maps in the 24-term exact…

Operator Algebras · Mathematics 2019-10-22 Jeffrey L. Boersema , Terry A. Loring

Let $F$ be the Fibonacci matrix $ \bigl[\begin{smallmatrix} 1 & 1 1 & 0 \\ \end{smallmatrix}\bigr] $. The Fibonacci Dyck shift is a subshsystem of the Dyck shift $D_2$ constrained by the matrix $F$. Let ${{\frak L}^{Ch(D_F)}}$ be a…

Operator Algebras · Mathematics 2007-05-23 Kengo Matsumoto

We consider a construction of C*-algebras from continuous piecewise monotone maps on the circle which generalizes the crossed product construction for homeomorphisms and more generally the construction of Renault, Deaconu and…

Operator Algebras · Mathematics 2019-02-20 Thomas L. Schmidt , Klaus Thomsen

The purpose of this paper is construct an embedding of the C*-algebra of the Cartan motion group of a real reductive group G into the reduced C*-algebra of G itself. The embedding has a number of applications: we shall use it to…

Representation Theory · Mathematics 2026-03-03 Pierre Clare , Nigel Higson , Angel Román

We establish some results about large restricted Lie algebras similar to those known in the Group Theory. As an application we use this group-theoretic approach to produce some examples of restricted as well as ordinary Lie algebras which…

Rings and Algebras · Mathematics 2007-05-23 Yuri Bahturin , Alexander Olshanskii

We begin the systematic model theoretic study of $\mathrm{C}^*$-algebras using the tools of continuous logic.

Logic · Mathematics 2018-04-17 I. Farah , B. Hart , M. Lupini , L. Robert , A. Tikuisis , A. Vignati , W. Winter

We consider two Z/2Z-actions on the Podles generic quantum spheres. They yield, as noncommutative quotient spaces, the Klimek-Lesniewski q-disc and the quantum real projective space, respectively. The C*-algebras of all these quantum spaces…

Quantum Algebra · Mathematics 2009-11-07 P. M. Hajac , R. Matthes , W. Szymanski

We give a survey of the meaning, status and applications of the Baum-Connes Conjecture about the topological K-theory of the reduced group C^*-algebra and the Farrell-Jones Conjecture about the algebraic K- and L-theory of the group ring of…

K-Theory and Homology · Mathematics 2007-05-23 Wolfgang Lueck , Holger Reich

We consider groups G which have a cocompact, 3-manifold model for the classifying space \underline{E}G. We provide an algorithm for computing the rationalized equivariant K-homology of \underline{E}G. Under the additional hypothesis that…

K-Theory and Homology · Mathematics 2013-04-30 Jean-François Lafont , Ivonne J. Ortiz , Rubén J. Sánchez-García

To a large class of graphs of groups we associate a C*-algebra universal for generators and relations. We show that this C*-algebra is stably isomorphic to the crossed product induced from the action of the fundamental group of the graph of…

Operator Algebras · Mathematics 2021-07-27 Nathan Brownlowe , Alexander Mundey , David Pask , Jack Spielberg , Anne Thomas

Exploiting the graph product structure and results concerning amalgamated free products of C*-algebras we provide an explicit computation of the K-theoretic invariants of right-angled Hecke C*-algebras, including concrete algebraic…

Operator Algebras · Mathematics 2022-06-14 Sven Raum , Adam Skalski

By using K-theory, we construct a map from the tangent space to the Hilbert scheme at a point Y to the local cohomology group. And we use this map to answer affirmatively(after slight modification) a question by Mark Green and Phillip…

Algebraic Geometry · Mathematics 2018-12-26 Sen Yang

We propose a generalization of K-theory to operator systems. Motivated by spectral truncations of noncommutative spaces described by $C^*$-algebras and inspired by the realization of the K-theory of a $C^*$-algebra as the Witt group of…

Operator Algebras · Mathematics 2024-09-05 Walter D. van Suijlekom

In this paper, we study the K-theory on higher modules in spectral algebraic geometry. We relate the K-theory of an $\infty$-category of finitely generated projective modules on certain $\mathbb{E}_{\infty}$-rings with the K-theory of an…

K-Theory and Homology · Mathematics 2016-08-08 Mariko Ohara