Topological full groups of ultragraph groupoids as an isomorphism invariant
We prove two isomorphism-invariance theorems for groupoids associated with ultragraphs.
These theorems characterize ultragraphs for which the topological full group of an …
These theorems characterize ultragraphs for which the topological full group of an …
Groupoids and Hermitian Banach*-algebras
A Austad, E Ortega - International Journal of Mathematics, 2022 - World Scientific
We study when the twisted groupoid Banach*-algebra L 1 (𝒢, σ) is Hermitian. In particular,
we prove that Hermitian groupoids satisfy the weak containment property. Furthermore, we …
we prove that Hermitian groupoids satisfy the weak containment property. Furthermore, we …
Studying Stein's Groups as Topological Full Groups
O Tanner - arXiv preprint arXiv:2312.07375, 2023 - arxiv.org
We include a class of generalisations of Thompson's group $ V $ introduced by Melanie
Stein into the growing framework of topological full groups. Like $ V $, Stein's groups can be …
Stein into the growing framework of topological full groups. Like $ V $, Stein's groups can be …
Shadowing, finite order shifts and ultrametric spaces
Inspired by a recent novel work of Good and Meddaugh, we establish fundamental
connections between shadowing, finite order shifts, and ultrametric complete spaces. We …
connections between shadowing, finite order shifts, and ultrametric complete spaces. We …
Generalisations of Thompson's group V arising from purely infinite groupoids
E Gardella, O Tanner - arXiv preprint arXiv:2302.04078, 2023 - arxiv.org
We study a class of generalisations of Thompson's group $ V $ arising naturally as
topological full groups of purely infinite, minimal groupoids. In the process, we show that the …
topological full groups of purely infinite, minimal groupoids. In the process, we show that the …
KMS states and continuous orbit equivalence for ultragraph shift spaces with sinks
FA Tasca, D Gonçalves - Publicacions matematiques, 2022 - projecteuclid.org
We extend ultragraph shift spaces and the realization of ultragraph C*-algebras as partial
crossed products to include ultragraphs with sinks (under a mild condition, called (RFUM2) …
crossed products to include ultragraphs with sinks (under a mild condition, called (RFUM2) …
Matui's AH conjecture for Graph Groupoids
P Nyland, E Ortega - Documenta Mathematica, 2021 - ems.press
We prove that Matui's AH conjecture holds for graph groupoids of infinite graphs. This is a
conjecture which relates the topological full group of an ample groupoid with the homology …
conjecture which relates the topological full group of an ample groupoid with the homology …
Boundary maps, germs and quasi-regular representations
M Kalantar, E Scarparo - Advances in Mathematics, 2022 - Elsevier
We investigate the tracial and ideal structures of C⁎-algebras of quasi-regular
representations of stabilizers of boundary actions. Our main tool is the notion of boundary …
representations of stabilizers of boundary actions. Our main tool is the notion of boundary …
Banach algebras associated to twisted\'{e} tale groupoids: simplicity and pure infiniteness
K Bardadyn, B Kwaśniewski, A McKee - arXiv preprint arXiv:2406.05717, 2024 - arxiv.org
We define reduced and essential Banach algebras associated to a twisted\'{e} tale (not
necessarily Hausdorff) groupoid $(\mathcal {G},\mathcal {L}) $ and extend some …
necessarily Hausdorff) groupoid $(\mathcal {G},\mathcal {L}) $ and extend some …
The groupoids of adaptable separated graphs and their type semigroups
Given an adaptable separated graph, we construct an associated groupoid and explore its
type semigroup. Specifically, we first attach to each adaptable separated graph a …
type semigroup. Specifically, we first attach to each adaptable separated graph a …