Yu Deng, Fields Medalist 2026: “IHES has a perfect atmosphere for research”

Yu Deng’s connection with IHES began in July 2018, when he was invited by his postdoctoral mentor, Nader Masmoudi, to collaborate on problems in inviscid damping. “Unfortunately we did not make much progress,” he recalls with a smile, “but it was a very nice first experience with IHES.”

That first stay was the beginning of a lasting relationship with the Institute. Yu Deng has visited IHES three times over the past two years, and has come to appreciate the particular way of working that the place makes possible. “The Institute is a very comfortable and relaxing place to work, and there are lots of discussions,” he says. “While I was there, I really enjoyed talking to people, walking around and thinking alone, and also walking around with people. It’s a quiet atmosphere, perfect for research.”

These stays have left a real mark on his research. “I have talked to a lot of people during my visits, permanent members of the Institute like Laure Saint-Raymond and Thierry Bodineau, and other visitors like Clément Mouhot and Toan Nguyen. These discussions have been really helpful in improving my work on the Boltzmann equation, and in inspiring new research directions.”

Asked to describe his research to a non-specialist audience, Yu Deng puts it this way: “In general I work on partial differential equations, particularly in connection with probability, exploring the role of randomness in the evolution of physical systems. Physically, this is close to statistical physics, including kinetic theory and quantum field theory.”

This work is at the heart of the lecture he is giving at the International Congress of Mathematicians in Philadelphia this July. “I will be talking about my work of the last few years on particle and wave kinetic theory, in particular the derivation of the Boltzmann equation and of the wave kinetic equation. I am really happy to have this chance to present my work. In my view, it is an important recognition not only of my work, but of this whole field of research.”

One thing, in any case, is certain: the story between Yu Deng and IHES is far from over. He will be back at the Institute for a week in September “and probably also some time next year.”

IHES extends its warmest congratulations to Yu Deng on this exceptional distinction and looks forward to welcoming him back very soon.