University of Toronto mathematician Jacob Tsimerman wins Fields Medal

'Big honour,' says 1st winner of prestigious prize at a Canadian institution

University of Toronto math professor Jacob Tsimerman has won a 2026 Fields Medal, the top global honour in mathematics.

He's the first mathematician based at a Canadian institution to win the award and the second Canadian. Manjul Bhargava, who is Canadian but based at Princeton University, won the award in 2014.

Tsimerman accepted the award at the International Mathematical Congress in Philadelphia on Thursday.

"It's a big honour, obviously, getting this award for me and my collaborators, who I'm very happy are being recognized, as well," he said.

Tsimerman stressed the importance of collaboration in mathematics in a video shown at the ceremony that also describes the work for which he's being recognized.

WATCH | Tsimerman and his work:Tsimerman won for his contribution "in the recasting of o-minimality as a fundamental method of arithmetic and complex algebraic geometry," said organizers, and for his role "in the proof of many central conjectures, including Griffiths' conjecture on the algebraicity of images of the period maps, and the Andre-Oort conjecture for Siegel modular varieties."

Adam Stinchcombe, a colleague and an associate professor of mathematics at the University of Toronto, said in order to come up with those proofs, Tsimerman developed new techniques that "can be used in other areas of math."

The medal and a cash prize are awarded to four mathematicians under 40 every four years by a committee of the International Mathematical Union. This year's other winners were Yu Deng of the University of Chicago, John Pardon of Stony Brook University and Hong Wang of New York University.

The awards are named after Canadian mathematician John Charles Fields and funded by a trust he established at the University of Toronto.

With a file from Sheehan Desjardins