The 20th Takagi Lectures
November 4 (Sat), 2017 (Sat)
10:05--11:05, 14:00--15:00
Graduate School of Mathematical Sciences
The University of Tokyo, Tokyo, Japan

The Donaldson--Thomas theory of threefolds,
or why is it interesting to count sheaves?
Andrei Okounkov
(Columbia University / Kyoto University)


My goal in these two lectures is to explain:
  1) what are the Donaldson--Thomas counts counting,
  2) how are these counts related to other parts of mathematics and mathematical physics,
  3) what are the elementary counts, from which all other ones could be, at least in principle, derived,
  4) how are the elementary counts described using geometric representation theory.
As this is, realistically, too much ground to cover in two lectures, I will try to describe what I personally consider to be the most important points and ideas, hoping that those who are interested will open the accompanying notes.