Robbert Dijkgraaf is about the most lucid expositor around on the topic of what now goes under the name “topological strings”. This week he’s been giving the Coxeter Lectures at the Fields Institute in Toronto, and the slides and audio of his introductory talk are now available on-line. I hope there will be similar materials for his other, more detailed talks.
Last week the Fields Institute hosted a workshop on topological strings and the talks are on-line, although in many cases just the audio of the talk is available, which is pretty hard to follow.