Speaker：Professor G. Seregin (University of Oxford)

Abstract:In this expository talk, I would like to address a deep connection between local regularity theory for the Navier-Stokes equations and existence or non-existence non-trivial ancient (backward) solutions to the homogenous Navier-Stokes system. In particular, it is explained that the existence of nontrivial, wild, bounded ancient solutions, for which certain scalar-invariant  quantity are bounded, is the necessary and sufficient condition for the existence of suitable weak solutions that elicit Type-I blowups.

Time：December 13th  15:00

Venue：Lecture Hall, 1st Floor, School of Mathematics and Statistics

Speaker Introduction:Professor G. Seregin graduated from the Leningrad Polytechnical Institute in 1979, now known as the Saint Petersburg State Polytechnical University, and continued to teach at the University after receiving his doctorate. Professor Seregin's research focuses on the mathematical theory of elasticity and fluid mechanics and has produced a number of internationally significant results. Since 2000, he has been the head of the Laboratory of Mathematical Physics, St. Petersburg Department of V.A. Steklov Mathematical Institute. In addition to the previous position, he also became a professor at the University of Oxford in 2007. Furthermore, he received the Sophja Kovalevskaya Prize from the Russian Academy of Sciences in 2003, and was invited to give a plenary talk at the International Congress of Mathematics in 2010.