Charles Fefferman

Charles Fefferman is an American mathematician who made fundamental contributions to analysis and partial differential equations. In the context of the Navier–Stokes problem, he is best known as the author of the official formulation of one of the "Millennium Problems" for the Clay Institute. In this formulation, he clearly stated the question of existence and smoothness of solutions to the Navier–Stokes equations in three-dimensional space, including the problem of possible blow-up in finite time. His work set the standard by which results in this field are evaluated. Although Fefferman himself did not prove either the existence or absence of blow-up, his formulation became the starting point for all subsequent research. In particular, it is cited by the authors of the 2026 OpenAI paper claiming finite-time blow-up with smooth force. Fefferman is also known for his deep results in harmonic analysis and function theory, for which he received the Fields Medal in 1978.