The approximately finite dimensional (AF) algebras have a deceptively simple description - they are the "locally finite dimensional" C*-algebras. However it can be difficult to identify which C*-algebras are AF. This problem has been solved for graph algebras, but is still unsolved for higher rank graph algebras. In this talk I will give examples of categories of paths whose C*-algebras we are able to identify as the continued fraction AF algebras of Effros and Shen. These are nonstandard presentations of AF algebras, as they arise as C*-algebras of non AF groupoids. The proof relies on the recent classification results for simple nuclear C*-algebras. This is joint work with Ian Mitscher.
Our C*-Seminar will still (as it was last year) be on Wednesdays, but the time will now be a bit different: 1:30-2:45 pm (Arizona time, no daylight savings), meeting both in person (WXLR A309) and via zoom.
Also new: it's now the ASUERAU C*-Seminar (so, joint with our friends Lara and Mitch at Embry-Riddle Aeronautical University up the road in Prescott).
(Please email the organizer John Quigg quigg@asu.edu to be put on the email list if you would like to receive the link to the zoom seminar.)
Jack Spielberg
Professor
Arizona State University