12 citations · 40 across the 9 of their papers we have counts for
10 papers
The local bisection hypothesis for twisted groupoid C*-algebras
Becky Armstrong, Jonathan H. Brown, Lisa Orloff Clark +4
In this note, we present criteria that are equivalent to a locally compact Hausdorff groupoid being effective. One of these conditions is that satisfies the "C*-algebraic l…
Completely positive approximations and inductive systems
Kristin Courtney
We consider inductive systems of C*-algebras with completely positive contractive connecting maps. We define a condition, called C*-encoding, which is sufficient for the limit of t…
Nuclearity and CPC*-systems
Kristin Courtney, Wilhelm Winter
We write arbitrary separable nuclear C*-algebras as limits of inductive systems of finite-dimensional C*-algebras with completely positive connecting maps. The characteristic featu…
Alexandrov groupoids and the nuclear dimension of twisted groupoid -algebras
Kristin Courtney, Anna Duwenig, Magdalena C. Georgescu +2
We consider a twist over an étale groupoid . When is principal, we prove that the nuclear dimension of the reduced twisted groupoid -algebra is bounded by…
Reconstruction of twisted Steinberg algebras
Becky Armstrong, Gilles G. de Castro, Lisa Orloff Clark +6
We show how to recover a discrete twist over an ample Hausdorff groupoid from a pair consisting of an algebra and what we call a quasi-Cartan subalgebra. We identify precisely whic…
Universal -algebras with the Local Lifting Property
Kristin E. Courtney
The Local Lifting Property (LLP) is a localized version of projectivity for completely positive maps between -algebras. Outside of the nuclear case, very few $\mathrm…
Twisted Steinberg algebras
Becky Armstrong, Lisa Orloff Clark, Kristin Courtney +3
We introduce twisted Steinberg algebras over a commutative unital ring . These generalise Steinberg algebras and are a purely algebraic analogue of Renault's twisted groupoid C*…
The universal C*-algebra of a contraction
Kristin Courtney, David Sherman
We say that a contractive Hilbert space operator is universal if there is a natural surjection from its generated C*-algebra to the C*-algebra generated by any other contraction. A…
Free products with amalgamation over central C*-subalgebras
Kristin Courtney, Tatiana Shulman
Let A and B be C*-algebras whose quotients are all RFD, and let C be a central C*-subalgebra in both A and B. We prove that the full amalgamated free product of A and B over C is t…
Elements of -algebras Attaining Their Norm in a Finite-Dimensional Representation
Kristin Courtney, Tatiana Shulman
We characterize the class of RFD -algebras as those containing a dense subset of elements that attain their norm under a finite-dimensional representation. We show further tha…