Date: Tuesday, November 8, 2022

Time: 5:00 – 6:00 p.m.

Location: Herzberg room 4351 (Macphail)

Title: An Example of a Locally Contracting Étale Groupoid

Speaker: Joseph Gondek, (master’s student, supervised by Prof. Charles Starling)

**Abstract.** Groupoids are algebraic objects that capture properties of groups, group actions, and topological spaces. Today, groupoids see significant utility in the theory of operator algebras: indeed, groupoid *C**-algebras give a wide class of useful and concrete *C**-algebras. In this talk, we build up the background needed to define a locally contracting étale groupoid, and produce an example of such a groupoid. To do this, we will define a groupoid and review several notions in topology in order to define a topological groupoid. We then define directed graphs, and construct a locally contracting étale groupoid from a particular directed graph.