Nuclear dimension of twisted groupoid C*-algebras
Groupoid models of C$^\ast$-algebras offer a way of exploring properties of a C$^\ast$-algebra by analyzing some features of the corresponding groupoid. One property of particular interest for operator algebraists is finite nuclear dimension, which plays a fundamental role in the classification program for simple nuclear C*-algebras.
In 2017, Guentner, Willett and Yu introduced dynamic asymptotic dimension, a notion of dimension for locally compact étale groupoids. Under the additional assumption that the groupoid $G$ is principal, they showed that the nuclear dimension of the reduced C$^\ast$-algebra of $G$ is bounded by a number depending on the dynamical asymptotic dimension of $G$ and the topological covering dimension of the unit space of $G$.
In this talk I will discuss some generalizations of the above result by focusing on twists over groupoids and étale groupoids with closed orbits and abelian stability subgroups. This is joint work with Astrid an Huef, Kristin Cortney. Anna Duwenig, and Magdalena Georgescu.