activity
20082020
most citedThe ideal structure of reduced crossed products

50 citations · 115 across the 13 of their papers we have counts for

collaborators

16 papers

math.OA2020

Structure theory and stable rank for C*-algebras of finite higher-rank graphs

David Pask, Adam Sierakowski, Aidan Sims

We study the structure and compute the stable rank of C*-algebras of finite higher-rank graphs. We completely determine the stable rank of the C*-algebra when the k-graph either co…

math.OA2020

Graded -theory and -homology of relative Cuntz-Pimsner algebras and graph -algebras

Quinn Patterson, Adam Sierakowski, Aidan Sims +1

We establish exact sequences in -theory for graded relative Cuntz-Pimsner algebras associated to nondegenerate -correspondences. We use this to calculate the graded -th…

math.RA2019

An algebraic analogue of Exel-Pardo C*-algebras

Roozbeh Hazrat, David Pask, Adam Sierakowski +1

We introduce an algebraic version of the Katsura -algebra of a pair of integer matrices and an algebraic version of the Exel-Pardo -algebra of a self-similar action…

math.OA2017

On the geometry of idempotents in von Neumann algebras

Thierry Giordano, Adam Sierakowski

We consider the general linear group as an invariant of von Neumann factors. We prove that up to complement, a set consisting of all idempotents generating the same right ideal adm…

math.OA2017★ 8 cited

Unbounded quasitraces, stable finiteness and pure infiniteness

David Pask, Adam Sierakowski, Aidan Sims

We prove that if A is a σ-unital exact C*-algebra of real rank zero, then every state on K_0(A) is induced by a 2-quasitrace on A. This yields a generalisation of Rainone's work on…

math.OA2015

Purely infinite simple C*-algebras that are principal groupoid C*-algebras

Jonathan H. Brown, Lisa Orloff Clark, Adam Sierakowski +1

From a suitable groupoid G, we show how to construct an amenable principal groupoid whose C*-algebra is a Kirchberg algebra which is KK-equivalent to C*(G). Using this construction…

math.OA2015★ 4 cited

Filling families and strong pure infiniteness

Eberhard Kirchberg, Adam Sierakowski

We introduce filling families with matrix diagonalization as a refinement of the work by Rørdam and the first named author. As an application we improve a result on local pure infi…

math.OA2015★ 1 cited

Real rank and topological dimension of higher rank graph algebras

David Pask, Adam Sierakowski, Aidan Sims

We study dimension theory for the -algebras of row-finite -graphs with no sources. We establish that strong aperiodicity - the higher-rank analogue of condition (K) - for a…

math.OA2014★ 19 cited

Purely infinite -algebras associated to étale groupoids

Jonathan Brown, Lisa Orloff Clark, Adam Sierakowski

Let be a Hausdorff, étale groupoid that is minimal and topologically principal. We show that is purely infinite simple if and only if all the nonzero positive elemen…

math.OA2014★ 1 cited

Twisted k-graph algebras associated to Bratteli diagrams

David Pask, Adam Sierakowski, Aidan Sims

Given a system of coverings of k-graphs, we show that the cohomology of the resulting (k+1)-graph is isomorphic to that of any one of the k-graphs in the system. We then consider B…

math.OA2014

The general linear group as a complete invariant for C*-algebras

Thierry Giordano, Adam Sierakowski

In 1955 Dye proved that two von Neumann factors not of type I_2n are isomorphic (via a linear or a conjugate linear *-isomorphism) if and only if their unitary groups are isomorphi…

math.OA2013★ 10 cited

Strong pure infiniteness of crossed products

Eberhard Kirchberg, Adam Sierakowski

Consider an exact action of discrete group on a separable -algebra . It is shown that the reduced crossed product is strongly purely infinite - prov…

math.OA2013★ 1 cited

Purely infinite partial crossed products

Thierry Giordano, Adam Sierakowski

Let (A,G,α) be a partial dynamical system. We show that there is a bijective correspondence between G-invariant ideals of A and ideals in the partial crossed product A xr G provide…

math.OA2011★ 2 cited

K-theory of certain purely infinite crossed products

G. A. Elliott, A. Sierakowski

It was shown by Rordam and the second named author that a countable group G admits an action on a compact space such that the crossed product is a Kirchberg algebra if, and only if…

math.OA2010★ 19 cited

Purely infinite C*-algebras arising from crossed products

Mikael Rordam, Adam Sierakowski

We study conditions that will ensure that a crossed product of a C*-algebra by a discrete exact group is purely infinite (simple or non-simple). We are particularly interested in t…

math.OA2008★ 50 cited

The ideal structure of reduced crossed products

Adam Sierakowski

Let (A,G) be a C*-dynamical system with G discrete. In this paper we investigate the ideal structure of the reduced crossed product C*-algebra and in particular we determine suffic…