Geometric Representation Theory Seminar - Winter 2008

John Baez and James Dolan

This winter, our seminar continues what we began in last quarter: studying geometric representation theory with the help of groupoidification. Last quarter we developed the basic idea of groupoidification, starting from scratch. This time we'll apply it to examples, starting with three closely related ones:

As before, this seminar is jointly run by John Baez and James Dolan, and we'll report on research we've done with Todd Trimble.

Also as before, here you can find videos and handwritten notes of the seminar, as well as links to blog entries at the n-Category Café, where you're encouraged to ask questions and make comments! If you can't figure out how the videos work, try this.

For much more on this subject, see:

Here are the lecture notes, videos and blog entries for this quarter:


We're offering the above videos in streaming and/or downloadable form, both as .mov files. Downloading them takes a long time, but you may need to do this, since the streaming videos seem to work well only if you have a good internet connection.

.mov files can best be played using a free program called QuickTime. If you have QuickTime and your web browser has .mov files associated to this program, you should be able to click on the "Streaming Video" links above and watch the videos. An alternate method is to launch the QuickTime player on your computer, click on "File" and then "Open URL", and type in the URLs provided above. This has the advantage that you can easily make the picture bigger.

If you can handle URL's that begin with rtsp, you can instead go the corresponding URL of that form, for example:


This may also have advantages, but at present my computer gags on such URL's, so I don't know.


If you catch mistakes, let me know and I'll add them to the list of errata. You can also see LaTeX, encapsulated PostScript and xfig files to download if for some bizarre reason you want them. However, we reserve all rights to this work.

© 2008 John Baez and James Dolan