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Related papers: On $q$-tensor products of Cuntz algebras

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We consider $C^*$-algebra $\mathcal{E}_{n,m}^q$, which is a $q$-twist of two Cuntz-Toeplitz algebras. For the case $|q|<1$ we give an explicit formula, which untwists the $q$-deformation, thus showing that the isomorphism class of…

Operator Algebras · Mathematics 2019-01-29 Alexey Kuzmin , Vasyl Ostrovskyi , Danylo Proskurin , Roman Yakymiv

We study a deformation of the Cuntz-Toeplitz $C^*$-algebra determined by the relations $a_i^*a_i=1+q a_ia_i^*, a_i^*a_j=0$. We define well-behaved unbounded *-representations of the *-algebra defined by relations above and classify all such…

Quantum Algebra · Mathematics 2009-11-13 Vasyl Ostrovskyi , Daniil Proskurin , Lyudmila Turowska

We consider the relations of generalized commutativity in the algebra of formal series $ M_q (x^i ) $, which conserve a tensor $ I_q $-grading and depend on parameters $ q(i,k) $ . We choose the $ I_q $-preserving version of differential…

High Energy Physics - Theory · Physics 2009-10-22 B. M. Zupnik

Let H(R,q) be an affine Hecke algebra with a positive parameter function q. We are interested in the topological K-theory of H(R,q), that is, the K-theory of its C*-completion C*_r (R,q). We will prove that $K_* (C*_r (R,q))$ does not…

K-Theory and Homology · Mathematics 2018-07-25 Maarten Solleveld

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

Let $\mathrm G$ be a connected semi-simple compact Lie group and for $0<q<1$, let $(\mathbb{C}[\mathrm{G]_q}],\Delta_q)$ be the Jimbo-Drinfeld $q$-deformation of $\mathrm G$. We show that the $C^*$-completions of $\mathrm{C}[\mathrm{G]_q}$…

Quantum Algebra · Mathematics 2019-11-12 Olof Giselsson

Let ${\cal A}_1$ be the class of all unital separable simple $C^*$-algebras $A$ such that $A\otimes U$ has tracial rank at most one for all UHF-algebras of infinite type. It has been shown that amenable ${\cal Z}$-stable $C^*$-algebras in…

Operator Algebras · Mathematics 2015-02-11 Huaxin Lin , Wei Sun

Let $A$ be a unital $C^*$-algebra, and let $\Sigma^2_m A$ denote the $m$-torsioned quantum double suspension of $A$. For $q \in (0,1)$ and $n \geq 1$, we prove that the $C^*$-algebra corresponding to the quotient space…

Operator Algebras · Mathematics 2026-02-20 Bipul Saurabh

We consider the C*-algebras O_2^q and A_2^q generated, respectively, by isometries s_1, s_2 satisfying the relation s_1^* s_2 = q s_2 s_1^* with |q| < 1 (the deformed Cuntz relation), and by isometries s_1, s_2 satisfying the relation s_2…

Operator Algebras · Mathematics 2007-05-23 Palle E. T. Jorgensen , Daniil P. Proskurin , Yurii S. Samoilenko

We prove that the Cuntz semigroup is recovered functorially from the Elliott invariant for a large class of C*-algebras. In particular, our results apply to the largest class of simple C*-algebras for which K-theoretic classification can be…

Operator Algebras · Mathematics 2007-08-22 Nathanial P. Brown , Francesc Perera , Andrew S. Toms

Let A be a simple, unital, exact, and finite C*-algebra which absorbs the Jiang-Su algebra Z tensorially. We prove that the Cuntz semigroup of A admits a complete order embedding into an ordered semigroup obtained from the Elliott invariant…

Operator Algebras · Mathematics 2007-05-23 Francesc Perera , Andrew S. Toms

For the $q$-deformed canonical commutation relations $a(f)a^\dagger(g) = (1-q)\,\langle f,g\rangle{\bf1}+q\,a^\dagger(g)a(f)$ for $f,g$ in some Hilbert space ${\cal H}$ we consider representations generated from a vector $\Omega$ satisfying…

funct-an · Mathematics 2016-08-31 P. E. T. Jørgensen , R. F. Werner

The aim of this paper is to announce the results on irreducible nonclassical type representations of the nonstandard q-deformations U'_q(so_n), U_q(iso_n) and U'_q(so_{n,1}) of the universal enveloping algebras of the Lie algebras so(n,C),…

Quantum Algebra · Mathematics 2007-05-23 N. Z. Iorgov , A. U. Klimyk

The aim of this paper is to give a complete classification of irreducible finite dimensional representations of the nonstandard q-deformation U'_q(so(n)) (which does not coincide with the Drinfeld-Jimbo quantum algebra U_q(so(n)) of the…

Quantum Algebra · Mathematics 2007-05-23 N. Z. Iorgov , A. U. Klimyk

Let $k$ be an algebraically-closed field, and let $B = kQ/I$ be a basic, finite-dimensional associative $k$-algebra with $n := \dim_kB < \infty$. Previous work shows that the collection of maximal subalgebras of $B$ carries the structure of…

Rings and Algebras · Mathematics 2019-02-25 Alexander H. Sistko

We introduce the notion of a homotopy of product systems, and show that the Cuntz-Nica-Pimsner algebras of homotopic product systems over N^k have isomorphic K-theory. As an application, we give a new proof that the K-theory of a 2-graph…

Operator Algebras · Mathematics 2024-08-16 James Fletcher , Elizabeth Gillaspy , Aidan Sims

In this article we survey some of the recent goings-on in the classification programme of C$^*$-algebras, following the interesting link found between the Cuntz semigroup and the classical Elliott invariant and the fact that the Elliott…

Operator Algebras · Mathematics 2009-02-20 Pere Ara , Francesc Perera , Andrew S. Toms

This paper establishes several fundamental structural properties of the $q$-Heisenberg algebra $\mathfrak{h}_n(q)$, a quantum deformation of the classical Heisenberg algebra. We first prove that when $q$ is not a root of unity, the global…

Rings and Algebras · Mathematics 2025-12-12 Mohammad H. M Rashid

For $n\in\mathbb{N}$ and $q\in [0,1[$, the Vaksman-Soibelman quantum sphere $S^{2n+1}_q$ is described by an associative algebra $\mathcal{A}(S^{2n+1}_q)$ deforming the algebra of polynomial functions on the 2n+1 dimensional unit sphere. Its…

Quantum Algebra · Mathematics 2025-07-16 Francesco D'Andrea

We study the Cuntz semigroup for non-simple $\text{C}^*$-algebras in this paper. In particular, we use the extended Elliott invariant to characterize the Cuntz comparison for $\text{C}^*$-algebras with the projection property which have…

Operator Algebras · Mathematics 2017-09-15 George Elliott , Kun Wang
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