The Mathematician Who Connected Particle Motion to Fluid Laws

Yu Deng became one of the leading mathematicians of his generation through breakthroughs in nonlinear dispersive equations, wave turbulence and kinetic theory. After studying at Peking University and MIT, he completed his Princeton doctorate in 2015 under Alexandru Ionescu. He later held positions at NYU and the University of Southern California before joining the University of Chicago. This documentary follows the work that helped place gas dynamics on rigorous foundations and earned the 2026 Fields Medal.

Physics describes gases at two very different scales: individual particles collide microscopically, while density, pressure and velocity obey fluid equations macroscopically. Proving that one description truly produces the other is a central part of Hilbert's sixth problem. Deng developed powerful analytic methods that closed a major gap between these scales. This documentary explains how rigorous mathematics can justify the laws used in physics and why the 2026 Fields Medal recognized a century-defining advance.