English
Related papers

Related papers: Extensions and Dilations of module maps

200 papers

Kadison and Kastler introduced a metric on the set of all C$^*$-algebras on a fixed Hilbert space. In this paper structural properties of C$^*$-algebras which are close in this metric are examined. Our main result is that the property of…

Operator Algebras · Mathematics 2010-08-16 Erik Christensen , Allan Sinclair , Roger R. Smith , Stuart White

We investigate the orthogonality preserving property for pairs of mappings on inner product $C^*$-modules extending existing results for a single orthogonality-preserving mapping. Guided by the point of view that the $C^*$-valued inner…

Operator Algebras · Mathematics 2025-04-29 Michael Frank , M. S. Moslehian , Ali Zamani

We construct an example of a Hilbert C*-module which shows that Troitsky's theorem on the geometrical essence of A-compact operators between Hilbert C*-modules is not extendable to a not countably generated module case (even in the case of…

Operator Algebras · Mathematics 2022-08-02 Denis Fufaev

We investigate from an algebraic and topological point of view the minimal prime spectrum of a universal algebra, considering the prime congruences w.r.t. the term condition commutator. Then we use the topological structure of the minimal…

Rings and Algebras · Mathematics 2024-09-04 George Georgescu , Leonard Kwuida , Claudia Mureşan

We study the C*-algebra of an affine map on a compact abelian group and give necessary and sufficient conditions for strong transitivity when the group is a torus. The structure of the C*-algebra is completely determined for all strongly…

Operator Algebras · Mathematics 2012-04-03 Kasper K. S. Andersen , Klaus Thomsen

We give a structural characterisation of linear operators from one $C^\ast$% -algebra into another whose adjoints map extreme points of the dual ball onto extreme points. We show that up to a $\ast$-isomorphism, such a map admits of a…

Functional Analysis · Mathematics 2016-09-06 Louis E. Labuschagne , Vania Mascioni

Given two C*-algebras A and B, abstract A-B bimodules that can be isometrically represented as operator bimodules are characterised in terms of their norm. Various properties of such bimodules are given. Their theory is very similar to…

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

B. Magajna and J. Schweizer showed in 1997 and 1999, respectively, that C*-algebras of compact operators can be characterized by the property that every norm-closed (and coinciding with its biorthogonal complement, resp.) submodule of every…

Operator Algebras · Mathematics 2025-04-29 Michael Frank

Bundles of C*-algebras can be used to represent limits of physical theories whose algebraic structure depends on the value of a parameter. The primary example is the $\hbar\to 0$ limit of the C*-algebras of physical quantities in quantum…

Operator Algebras · Mathematics 2021-05-26 Jeremy Steeger , Benjamin H. Feintzeig

We give a complete $K$-theoretical description of when an extension of two simple graph $C^{*}$-algebras is again a graph $C^{*}$-algebra.

Operator Algebras · Mathematics 2020-07-07 Søren Eilers , James Gabe , Takeshi Katsura , Efren Ruiz , Mark Tomforde

In a previous paper with Kashyap we generalized the theory of $W^*$-modules to the setting of modules over nonselfadjoint dual operator algebras, obtaining the class of weak*-rigged modules. The present paper and its contemporaneous…

Operator Algebras · Mathematics 2017-01-31 David P. Blecher

We show that certain extensions of classifiable C*-algebra are strongly classified by the associated six-term exact sequence in K-theory together with the positive cone of K_{0}-groups of the ideal and quotient. We apply our result to give…

Operator Algebras · Mathematics 2013-02-01 Soren Eilers , Gunnar Restorff , Efren Ruiz

We prove a complete analog of the Borsuk Homotopy Extension Theorem for arbitrary semiprojective C*-algebras. We also obtain some other results about semiprojective C*-algebras: a partial lifting theorem with specified quotient, a lifting…

Operator Algebras · Mathematics 2015-05-05 Bruce Blackadar

We investigate the deformation of involution and multiplication in a unital $C^*$-algebra when its norm is fixed. Our main result is to present all multiplications and involutions on a given $C^*$-algebra $\mathcal{A}$ under which…

Operator Algebras · Mathematics 2014-11-04 H. Najafi , M. S. Moslehian

We introduce a way of regarding Hilbert von Neumann modules as spaces of operators between Hilbert space, not unlike [Skei], but in an apparently much simpler manner and involving far less machinery. We verify that our definition is…

Quantum Algebra · Mathematics 2011-02-25 Panchugopal Bikram , Kunal Mukherjee , R. Srinivasan , V. S. Sunder

We study the problem of constructing a globalization for partial actions on *-algebras, C*-algebras and Hilbert modules. For the first ones we give a necessary condition for the existence of a globalization and we prove this conditions is…

Operator Algebras · Mathematics 2021-08-12 Damián Ferraro

This paper contains a quite detailed description of the C*-algebra arising from the transformation groupoid of a rational map of degree at least two on the Riemann sphere. The algebra is decomposed stepwise via extensions of familiar…

Operator Algebras · Mathematics 2012-02-14 Klaus Thomsen

A study of Hilbert $C^*$-bimodules over commutative $C^*$-algebras is carried out and used to establish a sufficient condition for two quantum Heisenberg manifolds to be isomorphic.

funct-an · Mathematics 2009-10-28 Beatriz Abadie , Ruy Exel

The semigroups of unital extensions of separable $C^\ast$-algebras come in two flavours: a strong and a weak version. By the unital $\mathrm{Ext}$-groups, we mean the groups of invertible elements in these semigroups. We use the unital…

Operator Algebras · Mathematics 2019-03-15 James Gabe , Efren Ruiz

We define E-theory for separable C*-algebras over second countable topological spaces and establish its basic properties. This includes an approximation theorem that relates the E-theory over a general space to the E-theories over finite…

K-Theory and Homology · Mathematics 2015-10-23 Marius Dadarlat , Ralf Meyer
‹ Prev 1 8 9 10 Next ›