The winners of the 2006 Fields Medals are Terence Tao and Grigori Perelman (as widely predicted), also Andrei Okounkov, and Wendelin Werner. For some more information, see the press releases at the ICM site.
Okounkov’s mathematical work has been in the area of representation theory and its links to combinatorics. His work in mathematical physics is well-known, relating random partitions and the statistical mechanics of certain crystals to Gromov-Witten and Seiberg-Witten theory (counting holomorphic curves and instantons). For some nice expository papers of his about this, see here, here, and here.
Wendelin Werner I know little about, his work involves 2d random walks and is related to CFT. There has been a lot of activity recently in this field, and there’s a related program going on this semester at the KITP. A friend wrote to me this morning to speculate that this is the same Wendelin Werner who at age 12 appeared in the film “La Passante du Sans-Souci”.
Update: Luca Trevisan is blogging from the conference.
Today the arXiv servers contain the message ” arXiv.org servers are currently under very heavy load due to demand for Grisha Perelman’s papers, published only as arXiv.org e-prints, which are available below.”