From July 15 to 19 in 2019, almost 4,000 mathematicians from over 100 countries attended the 9th International Congress on Industrial and Applied Mathematics (ICIAM 2019) in Valencia, Spain. Prof. Li Ruo from the School of Mathematical Sciences, Peking University, was invited to give an lecture titled "Globally hyperbolic regularization to Grad's moment system". In the lecture, he introduced the theory they recently developed on a model reduction framework for kinetic equations. As a systematic extension of the globally hyperbolic regularization for Grad’s moment method, the new theory in his lecture provides a framework on model reduction for generic kinetic equations, which ensures the reduced models to be symmetric hyperbolic, thus local well-posedness is attained. The theory is fundamental for the model reduction of kinetic equations. There are 27 invited lectures in total at ICIAM 2019.

About Li Ruo

Prof. Li Ruo got his Ph.D. degree in Peking University, 2001. He has revealed the underlying reason why the famous Grad's 13-moment system is not globally hyperbolic, and developed the globally hyperbolic regularization theory for all Grad's type moment systems. This essentially resolved the longstanding problem that Grad's moment system is lack of global hyperbolicity. He has developed algorithms and programs in pseudo-spectral method, to study scientific problems as finite time singularities of 3D in-compressible Euler equations, which clarified that the famous anti-parallel vortex tube configuration is impossible to produce a finite time singularity. He is the author of the numerical PDE software AFEPack, which is a finite element package with different adaptive mesh methods implemented, and has been extensively applied to kinds of problems in applications.