Master Class on classification of C*-algebras – University of Copenhagen


Master Class on the Classification of C*-algebras

The University of Copenhagen

November 16-27, 2009


Lecture Notes and Slides:

Click HERE to reach the site containing notes taken from the lecture series and slides from lecture series and from the junior seminar. To those of you who have not done so already, please send slides and lecture notes to Mikael Rørdam (email: 



Click below for the master class pictures taken by Tarje Bargheer:

Picture 1 - Picture 2 - Picture 3 - Picture 4 - Picture 5 - Picture 6 - Picture 7

Here  is the family graph made by Siri-Malén Høynes and Søren Møller.

Topics and purpose:

This Master Class is a part of, and supported by, the EU Marie Curie training program "EU-NCG - Network in Noncommutative Geometry" and of the center "Symmetri and deformations" at the University of Copenhagen. This is the first activity in the focused semester at the University of Copenhagen on operator algebra under the EU-NCG network. Additional activities are scheduled in January and February 2010. 

The Master Class is directed at pre- and postdocs, and has the aim to bring the participants up to date on selected current trends in the classification program of Elliott. There will be a number of lecture series given by the speakers listed below. A preliminary (and not entirely complete) program is now available (see below). The following topics - among others - will be covered:

  • The Cuntz semigroup and its relation to classification and non-classification
  • The Jiang-Su algebra and C*-algebras that tensorially absorb these
  • Purely infinite C*-algebras
  • Classification and finite decomposition rank
  • Classification of crossed products of C(X) by the integers
  • The Corona Factorization Property

We shall have a fairly light program with one 90 minutes talk in the morning and another in the afternoon (each with a 15 minutes break in the middle). There are talks by the participants (the junior seminar) late afternoon each day. 


  • Marius Dadarlat, Purdue University
  • George Elliott, University of Toronto
  • Ilan Hirshberg , Ben Gurion University of the Negev
  • Eberhard Kirchberg, Humboldt-Universität zu Berlin
  • Francesc Perera, Universitat Autònoma de Barcelona
  • Mikael Rørdam , University of Copenhagen
  • Andrew Toms, York University
  • Wilhelm Winter, University of Nottingham 

Program and titles of lecture series:

Click HERE for the program of the Master Class; and click HERE for titles of the lecture series. 

Titles and abstracts of talks in the junior seminar:

Each afternoon from 5 to 6 pm there will be two 20 minutes talk mostly by PhD students and postdocs. Click HERE for titles and abstracts of these talks.


Click HERE for the list of participants. 


The lectures will be held at the Department of Mathematics at the University of Copenhagen. You can find information for short term visitors including directions to the mathematics department HERE.


A block of rooms has been reserved at Hotel Cabinn City, a very centrally located hotel about 3 kilometers from the mathematics department, where the lectures are held. (One can walk, bicycle or take the bus between the hotel and the university.)

A standard single room is DKK 605, and a standard double room is DKK 795. Breakfast is included.

In order to make a reservation at this hotel you must fill the following FORM and fax or email it to the hotel. (Fax number and email address can be found on the form.) You have to enter your credit card number and CVC code on the form to guarantee payment for the first night accomodation.

Reservations must be made before October 15, 2009


The math departmen's How-to-find-us webpage tells you how to get to the department from various parts of town. There you can also find useful information about bus and train tickets and 10-trip cards.

From Copenhagen Airport to CabInn Hotel: Take the train (not the Metro) from the airport train station (track 2) to Copenhagen Central Station (Københavns Hovedbanegaard). The trains run every 10 minutes. (Buy ticket at the ticket counter at the level of the arrival at the airport.) The hotel is a 250 m walk from the central station (see MAP).

From Copenhagen Airport to Ibsens Hotel: Take the Metro to Nørreport Station (buy ticket at the ticket counter at the level of the arrival at the airport). The Metro runs every 3-6 minutes. Ibsens Hotel is a 400 m walk from Nørreport Metro station (see MAP).

From CabInn Hotel to the Math Department: It is a 4.5 km walk, quite nice if you have enough time and the weather permits - see MAP. Otherwise take the S-train from the Central Station (Københavns Hovedbanegaard) to Nørreport Station, and take bus no. 42, 43, 84, 185 or 150S from there to the university (see How-to-find-us webpage).

From Ibsens Hotel to the Math Department: This is explained on the How-to-find-us webpage. 


Participants who are affiliated with any node associated with the EU-NCG network in noncommutative geometry should get support from their own node. Ask your node coordinater. You can see the list of associated nodes HERE.

Participants not belonging to any of these nodes can apply for support from our local center "Symmetry and Deformation". You can do so by sending an email to Mikael Rørdam at no later than Friday October 2.


To register for the conference please fill this WEB FORM. On the form you can also indicate if you wish to give a talk.

Registration is free.