Jacob Tsimerman

Jacob Tsimerman (born April 26, 1988) is a Soviet-born Canadian mathematician at the University of Toronto specialising in arithmetic geometry, algebraic geometry, and related areas. He was awarded the SASTRA Ramanujan Prize in the year 2015 in recognition for his work on the André–Oort conjecture and for his work in both analytic number theory and algebraic geometry. In 2026, he received the Fields Medal for his work on O-minimality, Griffiths' conjecture, and the André–Oort conjecture. He attended the University of Toronto Schools for high school, where he represented Canada in the International Mathematical Olympiad in 2003 and 2004, winning gold medals both times with a perfect score in 2004.

Tsimerman began his post-secondary studies at University College, University of Toronto, at the age of 16, where he graduated after two years in 2006 with a bachelor's degree in mathematics. He obtained his PhD from Princeton in 2011 under the guidance of Peter Sarnak.

Career Following his PhD, he had a postdoctoral position at Harvard University as a Junior Fellow of the Harvard Society of Fellows. In July 2014, he was awarded a Sloan Fellowship, and he started his term as assistant professor in the Department of Mathematics at the University of Toronto, where he is now a full professor.

In 2018, Tsimerman was an invited speaker at the International Congress of Mathematicians (ICM). In 2019, he was awarded the Coxeter–James Prize by the Canadian Mathematical Society. He is also one of winners of the 2022 New Horizons in Mathematics Prize, associated with the Breakthrough Prize in Mathematics. He was awarded for "outstanding work in analytic number theory and arithmetic geometry, including breakthroughs on the André-Oort and Griffiths conjectures". In 2023, Tsimerman received the Ostrowski Prize. He was elected a Fellow of the Royal Society in 2025. Between 2025 and 2026, Tsimerman was a visiting professor at the Institute for Advanced Study.

In 2026, Tsimerman was awarded the Fields Medal at ICM Philadelphia 2026 for his "contribution in the recasting of o-minimality as a fundamental method of arithmetic and complex algebraic geometry, and his role in the proof of many central conjectures including Griffiths' conjecture on the algebraicity of images of the period maps, and the André-Oort conjecture for Siegel modular varieties." He became the first faculty member at a Canadian university to win the Fields Medal. There, he announced he was joining OpenAI as a researcher in AI safety.

Research Together with Jonathan Pila, Tsimerman demonstrated the André–Oort conjecture for Siegel modular varieties. Later, he completed the proof of the André–Oort conjecture for the Shimura variety by reducing the problem to the averaged Colmez conjecture which was proved by Xinyi Yuan and Shou-Wu Zhang as well as independently by Andreatta, Goren, Howard and Madapusi-Pera. In 2021, Tsimerman, Pila and Ananth Shankar published a full proof of the André–Oort conjecture.