47 citations · 303 across the 41 of their papers we have counts for
33 papers · 1 filter
Deformation of Fell bundles
Alcides Buss, Siegfried Echterhoff
In this paper we study deformations of -algebras that are given as cross-sectional -algebras of Fell bundles over locally compact groups . Our deformation comes from a…
A new approach to deformation of C*-algebras via coactions
Alcides Buss, Siegfried Echterhoff
We revisit the procedure of deformation of -algebras via coactions of locally compact groups and extend the methods to cover deformations for maximal, reduced, and exotic coac…
-theory of non-commutative Bernoulli Shifts
Sayan Chakraborty, Siegfried Echterhoff, Julian Kranz +1
For a large class of C*-algebras , we calculate the -theory of reduced crossed products of Bernoulli shifts by groups satisfying the Baum--Connes co…
Inclusions of -algebras arising from fixed-point algebras
Siegfried Echterhoff, Mikael Rørdam
We examine inclusions of -algebras of the form , where and are groups acting on a unital simple -algebra by outer automorphisms…
Amenability and weak containment for actions of locally compact groups on -algebras
Alcides Buss, Siegfried Echterhoff, Rufus Willett
In this work we introduce and study a new notion of amenability for actions of locally compact groups on -algebras. Our definition extends the definition of amenability for ac…
-Operator systems and crossed products
Massoud Amini, Siegfried Echterhoff, Hamed Nikpey
The purpose of this paper is to introduce a consistent notion of universal and reduced crossed products by actions and coactions of groups on operator systems and operator spaces.…
Injectivity, crossed products, and amenable group actions
Alcides Buss, Siegfried Echterhoff, Rufus Willett
This paper is motivated primarily by the question of when the maximal and reduced crossed products of a --algebra agree (particularly inspired by results of Matsumura and S…
The maximal injective crossed product
Alcides Buss, Siegfried Echterhoff, Rufus Willett
A crossed product functor is said to be injective if it takes injective morphisms to injective morphisms. In this paper we show that every locally compact group admits a maxima…
The minimal exact crossed product
Alcides Buss, Siegfried Echterhoff, Rufus Willett
Given a locally compact group , we study the smallest exact crossed-product functor on the category of --dynamical systems. As a…
Crossed products of operator spaces
Massoud Amini, Siegfried Echterhoff, Hamed Nikpey
Let be an operator space and $\iso(V)$ be the group of all completely isometric bijective linear mappings on . Let act on via a strongly continuous group homomorphis…
Exotic Crossed Products
Alcides Buss, Siegfried Echterhoff, Rufus Willett
An exotic crossed product is a way of associating a C*-algebra to each C*-dynamical system that generalizes the well-known universal and reduced crossed products. Exotic crossed pr…
Maximality of dual coactions on sectional C*-algebras of Fell bundles and applications
Alcides Buss, Siegfried Echterhoff
In this paper we give a simple proof of the maximality of dual coactions on full cross-sectional C*-algebras of Fell bundles over locally compact groups. As applications we extend…
Rieffel proper actions
Alcides Buss, Siegfried Echterhoff
In the late 1980's Marc Rieffel introduced a notion of properness for actions of locally compact groups on C*-algebras which, among other things, allows the construction of general…
Exotic crossed products and the Baum-Connes conjecture
Alcides Buss, Siegfried Echterhoff, Rufus Willett
We study general properties of exotic crossed-product functors and characterise those which extend to functors on equivariant C*-algebra categories based on correspondences. We sho…
Non-Commutative T-Duality
Siegfried Echterhoff, Ansgar Schneider
A duality theory of bundles of C-algebras whose fibres are twisted transformation group algebras is established. Classical T-duality is obtained as a special case, where all fi…
Weakly proper group actions, Mansfield's imprimitivity and twisted Landstad duality
Alcides Buss, Siegfried Echterhoff
Using the theory of weakly proper actions of locally compact groups recently developed by the authors, we give a unified proof of both reduced and maximal versions of Mansfield's I…
Imprimitivity theorems for weakly proper actions of locally compact groups
Alcides Buss, Siegfried Echterhoff
In a recent paper the authors introduced universal and exotic generalized fixed-point algebras for weakly proper group actions on C*-algebras. Here we extend the notion of weakly p…
Universal and exotic generalized fixed-point algebras for weakly proper actions and duality
Alcides Buss, Siegfried Echterhoff
Given a C*-dynamical system (A,G,α), we say that A is a weakly proper (X\rtimes G)-algebra if there exists a proper G-space X together with a nondegenerate G-equivariant *-homomorp…
Structure of crossed products by strictly proper actions on continuous-trace algebras
Siegfried Echterhoff, Dana P. Williams
We examine the ideal structure of crossed products B\rtimes G where B is a continuous-trace C*-algebra and the induced action of G on the spectrum of B is proper. In particular, we…
On the K-theory of crossed products by automorphic semigroup actions
Joachim Cuntz, Siegfried Echterhoff, Xin Li
Let P be a semigroup that admits an embedding into a group G. Assume that the embedding satisfies a certain Toeplitz condition and that the Baum-Connes conjecture holds for G. We p…
The primitive ideal space of the C*-algebra of the affine semigroup of algebraic integers
Siegfried Echterhoff, Marcelo Laca
We give a complete description of the primitive ideal space of the C*-algebra associated to the ring of integers R in a number field K as considered in a recent paper by Cuntz, Den…
On the K-theory of the C*-algebra generated by the left regular representation of an Ore semigroup
Joachim Cuntz, Siegfried Echterhoff, Xin Li
We compute the K-theory of C*-algebras generated by the left regular representation of left Ore semigroups satisfying certain regularity conditions. Our result describes the K-theo…
Crossed products and the Mackey-Rieffel-Green machine
Siegfried Echterhoff
We give an introduction into the ideal structure and representation theory of crossed products by actions of locally compact groups on C*-algebras. In particular, we discuss the Ma…
KK-theoretic duality for proper twisted actions
Siegfried Echterhoff, Heath Emerson, Hyun Jeong Kim
Let the discrete group G act properly and isometrically on the Riemannian manifold X. Let C_0(X, δ) be the section algebra of a smooth locally trivial G-equivariant bundle of eleme…