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Related papers: Positivstellensatz for C*-tensor categories

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In this paper, we collect some technical results about weights on C*-algebras which are useful in de theory of locally compact quantum groups in the C*-algebra framework. We discuss the extension of a lower semi-continuous weight to a…

Operator Algebras · Mathematics 2007-05-23 Johan Kustermans , Stefaan Vaes

We develop a tensor categorical duality in the sprit of the Tannaka-Krein duality for the C*-algebras admitting the Yetter-Drinfeld module structure over a compact quantum group. Under this duality, given a reduced compact quantum group G,…

Operator Algebras · Mathematics 2026-03-16 Lucas Hataishi , Makoto Yamashita

We will show a centrally free action of an amenable rigid C$^*$-tensor category on a properly infinite von Neumann algebra has the Rohlin property. This enables us to prove the fullness of the crossed product of a full factor by minimal…

Operator Algebras · Mathematics 2018-12-12 Reiji Tomatsu

The notion of extension of a given $C^*$-category $C$ by a $C^*$-algebra $A$ is introduced. In the commutative case $A = C(\Omega)$, the objects of the extension category are interpreted as fiber bundles over $\Omega$ of objects belonging…

Operator Algebras · Mathematics 2011-11-18 Ezio Vasselli

In this paper, we introduce the countable chain condition for C*-algebras and study its fundamental properties. We show independence from ZFC of the statement that this condition is preserved under the tensor products of C*-algebras.

Operator Algebras · Mathematics 2014-05-07 Shuhei Masumoto

T*-categories are introduced as a ternary generalization of C*-categories. Their linking C*-categories are constructed and the Gelfand-Naimark representation theorems of Zettl for C*-ternary rings and for W*-ternary rings, are generalized…

Operator Algebras · Mathematics 2023-05-24 Robert Pluta , Bernard Russo

Given a Hausdorff compact space X, we study the C^*-(semi)-norms on the algebraic tensor product $A\otimes_{alg,C(X)} B$ of two C(X)-algebras A and B over C(X). In particular, if one of the two C(X)-algebras defines a continuous field of…

Operator Algebras · Mathematics 2016-09-07 Etienne Blanchard

We classify semisimple module categories over the tensor category of representations of quantum SL(2) extending previous results to the roots of unity and positive characteristic cases.

Quantum Algebra · Mathematics 2007-05-23 Victor Ostrik

The notion of almost elementariness for a locally compact Hausdorff \'{e}tale groupoid $\mathcal{G}$ with a compact unit space was introduced by the authors as a sufficient condition ensuring the reduced groupoid $C^*$-algebra…

Operator Algebras · Mathematics 2024-07-09 Xin Ma , Jianchao Wu

In this paper we consider we study various classical operator ideals (for instance, the ideals of strictly (co)singular, weakly compact, Dunford-Pettis operators) either on $C^*$-algebras, or preduals of von Neumann algebras.

Operator Algebras · Mathematics 2013-09-24 T. Oikhberg , E. Spinu

We prove that the category of abstract Cuntz semigroups is bicomplete. As a consequence, the category admits products and ultraproducts. We further show that the scaled Cuntz semigroup of the (ultra)product of a family of C*-algebras agrees…

Operator Algebras · Mathematics 2020-05-27 Ramon Antoine , Francesc Perera , Hannes Thiel

We present a new method, involving monads and comonads from category theory, to help establish a certain type of equivalence of subcategories. As a case study we consider the category of topological gradings of $C^*$-algebras over a fixed…

Operator Algebras · Mathematics 2025-12-09 Erik Bédos , S. Kaliszewski , John Quigg

This paper introduces methods for classifying actions of finite-dimensional Hopf algebras on path algebras of quivers, and more generally on tensor algebras $T_B(V)$ where $B$ is semisimple. We work within the broader framework of finite…

Quantum Algebra · Mathematics 2019-12-11 Pavel Etingof , Ryan Kinser , Chelsea Walton

We apply the machinery of relative tensor triangular Chow groups to the action of the derived category of quasi-coherent sheaves on a noetherian scheme $X$ on the derived category of quasi-coherent $\mathcal{A}$-modules, where $\mathcal{A}$…

Algebraic Geometry · Mathematics 2019-02-05 Pieter Belmans , Sebastian Klein

We develop a general framework to deal with the unitary representations of quantum groups using the language of C*-algebras. Using this framework, we prove that the duality holds in a general context. This extends the framework of the…

Quantum Algebra · Mathematics 2007-05-23 T. Masuda , Y. Nakagami , S. L. Woronowicz

We introduce a bivariant version of the Cuntz semigroup as equivalence classes of order zero maps generalizing the ordinary Cuntz semigroup. The theory has many properties formally analogous to KK-theory including a composition product. We…

Operator Algebras · Mathematics 2016-02-08 Joan Bosa , Gabriele Tornetta , Joachim Zacharias

In this paper we investigate a *-algebra $\cX$ of fractions associated with a unital complex *-algebra $\cA$. The algebra $\cX$ and its Hilbert space representations are used to prove abstract noncommutative strict Positivstellens\"atze for…

Operator Algebras · Mathematics 2009-03-17 Konrad Schmuedgen

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

We classify extensions of certain classifiable C*-algebras using the six term exact sequence in K-theory together with the positive cone of the K_0-groups of the distinguished ideal and quotient. We then apply our results to a class of…

Operator Algebras · Mathematics 2014-10-01 Soren Eilers , Gunnar Restorff , Efren Ruiz

C*-algebras are widely used in mathematical physics to represent the observables of physical systems, and are sometimes taken as the starting point for rigorous formulations of quantum mechanics and classical statistical mechanics.…

Functional Analysis · Mathematics 2007-05-23 Miguel Carrion-Alvarez