Back from San Diego, recovering from the redeye. It was a terrific Joint Math Meetings this year; I saw lots of old friends and great talks, but had to miss a lot of both, too.
A couple of people asked me for the slides of my talk, “How To Count with Topology.” Here they are, in .pdf:
If you find this stuff interesting, these blog posts give a somewhat more detailed sketch of the papers with Venkatesh and Westerland I talked about.
Quomodocumque 