English
Related papers

Related papers: A note on spectral triples and quasidiagonality

200 papers

It is shown that the spectral radius is continuous on a $C^*$-algebra if and only if the $C^*$-algebra is type I. This answers a question of V. Shulman and Yu.~Turovskii [10]. It is shown also that the closure of nilpotents in a…

Operator Algebras · Mathematics 2018-04-05 Tatiana Shulman

The aim of this paper is to study quasitriangular structures on a class of semisimple Hopf algebras constructed through abelian extensions of $Z_2$ for an abelian group $G$. We prove that there are only two forms of them. Using such…

Quantum Algebra · Mathematics 2020-07-21 Kun Zhou , Gongxiang Liu

We describe how noncommutative function algebras built from noncommutative functions in the sense of \cite{K-VV2014} may be studied as subalgebras of homogeneous $C^{*}$-algebras.

Operator Algebras · Mathematics 2015-11-02 Erin Griesenauer , Paul S. Muhly , Baruch Solel

We show that the first five of the axioms we had formulated on spectral triples suffice (in a slightly stronger form) to characterize the spectral triples associated to smooth compact manifolds. The algebra, which is assumed to be…

Operator Algebras · Mathematics 2008-10-14 Alain Connes

We provide criteria for the cyclotomic quiver Hecke algebras of type C to be semisimple. In the semisimple case, we construct the irreducible modules.

Representation Theory · Mathematics 2018-02-20 Liron Speyer

In order to study the Hochschild cohomology of triangular algebras $\mathcal T$, we construct a spectral sequence, whose terms are parametrized by the length of the trajectories of the quiver associated with $\mathcal T$, and which…

Rings and Algebras · Mathematics 2007-05-23 Sophie Dourlens

The structure of heterotic string target space compactifications is studied using the formalism of the noncommutative geometry associated with lattice vertex operator algebras. The spectral triples of the noncommutative spacetimes are…

High Energy Physics - Theory · Physics 2009-10-31 David D. Song , Richard J. Szabo

We show that every unitary representation of a solvable discrete virtually nilpotent group G is quasidiagonal. Roughly speaking, this says that every unitary representation of G approximately decomposes as a direct sum of finite dimensional…

Operator Algebras · Mathematics 2014-01-23 Caleb Eckhardt

It is shown that the compact Lie group SU(3) admits an Sp(2)Sp(1)-structure whose distinguished 2-forms $\omega_1,\omega_2,\omega_3$ span a differential ideal. This is achieved by first reducing the structure further to a subgroup…

Differential Geometry · Mathematics 2010-04-02 Oscar Macia

We introduce quasi-Hopf $*$-algebras i.e. quasi-Hopf algebras equipped with a conjugation (star) operation. The definition of quasi-Hopf $*$-algebras proposed ensures that the class of quasi-Hopf $*$-algebras is closed under twisting and…

Quantum Algebra · Mathematics 2007-05-23 M. D. Gould , T. Lekatsas

We describe $\sigma$-matching, interchangeable and, as a consequence, totally compatible products on some classes of associative algebras, including unital algebras, the semigroup algebras of rectangular bands, algebras with enough…

Rings and Algebras · Mathematics 2025-10-22 Mykola Khrypchenko

A classification is given of certain separable nuclear C*-algebras not necessarily of real rank zero, namely the class of simple C*-algebras which are inductive limits of continuous-trace C*-algebras whose building blocks have their…

Operator Algebras · Mathematics 2007-05-23 C. Ivanescu

We explicitly construct Fredholm modules and spectral triples representing any element of $K$-homology groups of Hensel-Steinitz algebras.

Operator Algebras · Mathematics 2025-10-09 Shelley Hebert , Slawomir Klimek , Matt McBride

Deformations of the canonical spectral triples over the n-dimensional torus are considered. These deformations have a discrete dimension spectrum consisting of non-integer values less than n. The differential algebra corresponding to these…

Mathematical Physics · Physics 2012-01-23 R. Trinchero

We construct 3-manifolds which have at least two inequivalent embeddings such that both complementary regions have abelian fundamental group.

Geometric Topology · Mathematics 2025-06-05 Jonathan A. Hillman

A way to construct and classify the three dimensional polynomially deformed algebras is given and the irreducible representations is presented. for the quadratic algebras 4 different algebras are obtained and for cubic algebras 12 different…

Mathematical Physics · Physics 2007-05-23 Bindu A. Bambah

We demonstrate that pure C*-algebras form a robust class by proving that pureness follows from very weak comparison and divisibility properties. Using this, we show that every simple, non-elementary C*-algebra with a unique quasitrace and…

Operator Algebras · Mathematics 2024-12-18 Ramon Antoine , Francesc Perera , Hannes Thiel , Eduard Vilalta

A class of three-dimensional models which satisfy supersymmetric intertwining relations with the simplest - oscillator-like - variant of shape invariance is constructed. It is proved that the models are not amenable to conventional…

High Energy Physics - Theory · Physics 2015-06-12 M. S. Bardavelidze , F. Cannata , M. V. Ioffe , D. N. Nishnianidze

The class of separable C*-algebras which can be written as inductive limits of continuous-trace C*-algebras with spectrum homeomorphic to a disjoint union of trees and trees with a point removed is classified by the Cuntz semigroup.

Operator Algebras · Mathematics 2010-04-05 Alin Ciuperca , George A. Elliott , Luis Santiago

One way to obtain Quantized Universal Enveloping Algebras (QUEAs) of non-semisimple Lie algebras is by contracting QUEAs of semisimple Lie algebras. We prove that every contracted QUEA in a certain class is a cochain twist of the…

Quantum Algebra · Mathematics 2014-11-18 C. A. S. Young , R. Zegers