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Related papers: Inductive limit violates quasi-cocommutativity

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Inspired by the commutator and anticommutator algebras derived from algebras graded by groups, we introduce noncommutatively graded algebras. We generalize various classical graded results to the noncommutatively graded situation concerning…

Rings and Algebras · Mathematics 2017-11-01 Patrik Nystedt

In the current article, we prove the cross product $C^*$-algebra by a Rokhlin action of finite group on a strongly quasidiagonal $C^*$-algbra is strongly quasidiagonal again. We also show that a just-infinite $C^*$-algebra is quasidiagonal…

Operator Algebras · Mathematics 2019-11-26 Qihui Li

We describe the $C^*$-algebra of an $E$-unitary or strongly 0-$E$-unitary inverse semigroup as the partial crossed product of a commutative $C^*$-algebra by the maximal group image of the inverse semigroup. We give a similar result for the…

Operator Algebras · Mathematics 2015-12-08 David Milan , Benjamin Steinberg

We present a systematic development of inductive limits in the categories of ordered *-vector spaces, Archimedean order unit spaces, matrix ordered spaces, operator systems and operator C*-systems. We show that the inductive limit…

Operator Algebras · Mathematics 2017-05-15 Linda Mawhinney , Ivan G. Todorov

Let $M_{*}({\bf C})$ denote the C$^{*}$-algebra defined as the direct sum of all matrix algebras $\{M_{n}({\bf C}):n\geq 1\}$. It is known that $M_{*}({\bf C})$ has a non-cocommutative comultiplication $\Delta_{\varphi}$. We show that the…

Operator Algebras · Mathematics 2010-01-13 Katsunori Kawamura

We introduce and analyse a new type of quantum 2-spheres. Then we apply index theory for noncommutative line bundles over these spheres to conclude that quantum lens spaces are non-crossed-product examples of principal extensions of…

K-Theory and Homology · Mathematics 2007-05-23 Piotr M. Hajac , Rainer Matthes , Wojciech Szymanski

A deductive system is structurally complete if its admissible inference rules are derivable. For several important systems, like modal logic S5, failure of structural completeness is caused only by the underivability of passive rules, i.e.…

Logic · Mathematics 2014-08-26 Wojciech Dzik , Michal M. Stronkowski

We study the derived invariance of the cohomology theories $Hoch^*$, $H^*$ and $HC^*$ associated to coalgebras over a field. We prove a theorem characterizing derived equivalences. As particular cases, it describes the two following…

K-Theory and Homology · Mathematics 2007-05-23 Marco A. Farinati

We investigate when the categories of all rational $A$-modules and of finite dimensional rational modules are closed under extensions inside the category of $C^*$-modules, where $C^*$ is the cofinite topological completion of $A$. We give a…

Category Theory · Mathematics 2011-10-13 Miodrag C. Iovanov

We introduce the quasi-Poisson enveloping algebra and Poisson enveloping algebra for a non-commutative Poisson algebra. We prove that for a non-commutative Poisson algebra, the category of quasi-Poisson modules is equivalent to the category…

Rings and Algebras · Mathematics 2010-12-14 Yan-Hong Yang , Yuan Yao , Yu Ye

Convolution semigroups of states on a quantum group form the natural noncommutative analogue of convolution semigroups of probability measures on a locally compact group. Here we initiate a theory of weakly continuous convolution semigroups…

Operator Algebras · Mathematics 2009-10-28 J. Martin Lindsay , Adam Skalski

We propose a general scheme for the "logic" of elementary propositions of physical systems, encompassing both classical and quantum cases, in the framework given by Non Commutative Geometry. It involves Baire*-algebras, the non-commutative…

Quantum Physics · Physics 2007-05-23 P. A. Marchetti , R. Rubele

K-Theory for hermitian symmetric spaces of non-compact type, as developed recently by the authors, allows to put Cartan's classification into a homological perspective. We apply this method to the case of inductive limits of finite…

K-Theory and Homology · Mathematics 2016-09-23 Dennis Bohle , Wend Werner

We study operator spaces, operator algebras, and operator modules, from the point of view of the `noncommutative Shilov boundary'. In this attempt to utilize some `noncommutative Choquet theory', we find that Hilbert C$^*-$modules and their…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher

It is determined exactly which classifiable C*-algebras have approximately inner flip. The answer includes a number of C*-algebras with torsion in their K-theory, and a number of C*-algebras that are self-absorbing but not strongly…

Operator Algebras · Mathematics 2016-01-11 Aaron Tikuisis

We prove that an infinite-ended group whose one-ended factors have finite-index subgroups and are in a family of groups with a nonzero multiplicative invariant is not quasi-isometrically rigid. Combining this result with work of the first…

Group Theory · Mathematics 2023-10-06 Nir Lazarovich , Emily Stark

Given a compact, metric space X, we show that the commutative C*-algebra C(X) is semiprojective if and only if X is an absolute neighborhood retract of dimension at most one. This confirms a conjecture of Blackadar. Generalizing to the…

Operator Algebras · Mathematics 2013-02-05 Adam P. W. Sørensen , Hannes Thiel

A pro-C^*-algebra is a (projective) limit of C^*-algebras in the category of topological *-algebras. From the perspective of non-commutative geometry, pro-C^*-algebras can be seen as non-commutative k-spaces. An element of a pro-C^*-algebra…

Category Theory · Mathematics 2011-09-27 Rachid El Harti , Gábor Lukács

We discuss a number of general constructions concerning additive $ C^* $-categories, focussing in particular on establishing the existence of bicolimits. As an illustration of our results we show that balanced tensor products of module…

Operator Algebras · Mathematics 2020-06-12 Jamie Antoun , Christian Voigt

We write arbitrary separable nuclear C*-algebras as limits of inductive systems of finite-dimensional C*-algebras with completely positive connecting maps. The characteristic feature of such CPC*-systems is that the maps become more and…

Operator Algebras · Mathematics 2024-10-10 Kristin Courtney , Wilhelm Winter