Semester page for MAT9390 - Spring 2026

Due to a PhD defense on January 23, we will instead have the lecture the day before, on Thursday January 22 in room 720 in Niels Henrik Abels Hus at 14:15. If this time is inconvenient, please contact me.

I will base the lecture notes on material from the following books:

• Dana Williams: A toolkit for groupoid C*-algebras
• Claire Anantharaman-Delaroche and Jean Renault: Amenable groupoids
• Alan L. T. Paterson: Groupoids, Inverse Semigroups and their Operator Algebras
• Aidan Sims: Lecture notes on ¨¦tale groupoids and their C*-algebras

The theme of MAT9390 this spring will be groupoids and their operator algebras. I plan to focus on topological groupoids and their C*-algebras, but hopefully also cover some aspects of measured groupoids and their von Neumann algebras.

The topics I plan on covering, or at least touch upon, are the following:

• Unitary representation theory of groupoids
• Equivalence of groupoids
• Amenability of groupoids
• Kumjian-Renault theory for twisted groupoids and Cartan subalgebras

I will publish lecture notes as the lectures progress.

The set lecture times are Mondays 14:15-16:00 and Fridays 10:15-12:00 in room NHA1020, with the first lecture being on Monday January 19th.