Philipp Sibbel

collaborators

4 papers

math.OA2026

Principal groupoid models for stable UCT Kirchberg algebras

Samuel Evington, Philipp Sibbel

We show that every stable UCT Kirchberg algebra has a principal Ã©tale groupoid model, and thus contains a C $^{*}$ -diagonal. Every unital UCT Kirchberg algebra $A$ for which $[1_A]_0…

math.OA2026

C*-diagonals with Cantor spectrum in Cuntz algebras

Samuel Evington, Philipp Sibbel

We prove that there exists a C*-diagonal with Cantor spectrum in the Cuntz algebra $O_{k}$ for $2 \leq k < \infty$ . Our method generalises to an uncountable family of UCT Ki…

math.OA2025

Principal Groupoid Models for Cuntz Algebras and their Dynamic Asymptotic Dimension

Samuel Evington, Philipp Sibbel

We compute the dynamic asymptotic dimension of the principal groupoid models for the Cuntz algebras $O_{k}$ for $2 \leq k < \infty$ that have arisen from work of Winter and…

math.OA2025

A Cantor spectrum diagonal in O_2

Philipp Sibbel, Wilhelm Winter

We prove the existence of a C*-diagonal in the Cuntz algebra O_2 with spectrum homeomorphic to the Cantor space.