Analysis and applications of nonlinear partial differential equations in conservation laws and kinetic theories

New York University, New York NY

Investigators

Abstract

The principal investigator will study mathematical problems of certain nonlinear partial differential equations in fluid dynamics and the kinetic theory, such as the compressible relativistic Navier-Stokes equation, the magnetohydrodynamics (MHD) equations without the magnetic diffusivity, the compressible viscoelastic flows, and the Vlasov-Maxwell-Boltzmann equations. These equations model a variety of physical processes requiring significantly new mathematical approaches, and understanding of properties of these models is a fundamental challenge both from the mathematical and physical viewpoints. The research program consists of four parts: (1) The first part concerns the global existence of weak solutions of the relativistic Navier-Stokes equation and some qualitative properties of weak solutions. Compactness theory and the kinetic formulation will be explored. (2) The second part regards the global existence of strong solutions to the magnetohydrodynamics without magnetic diffusivity. The decay of the component of the magnetic field which is parallel to the equilibrium will be fully developed. (3) The third part considers the incompressible limit of the compressible viscoelastic fluids and the weak solutions to the two dimensional steady compressible viscoelastic fluids. The oscillation of the asymptotic solutions will be exploited. (4) The fourth part studies the Vlasov-Maxwell-Boltzmann equations. Topics that to be addressed include the global existence of the renormalized solution and its hydrodynamic limit. The mathematical problems to be investigated in the project arise in many scientific disciplines including plasma physics, elastodynamics, astrophysics, fluid dynamics, and the dynamics of biological and chemical reactions. The mathematical issues, such as global existence, incompressible limits, and hydrodynamic limits are of fundamental importance in biology, engineering, and physics. The primary goal of this research program is to provide mathematical verification of the fundamental models, to find a connection among these models, and to investigate analytical properties that will yield new insight into the mathematics of fluids, critical for plasma physics, elastodynamics, and other physical models, which could facilitate better understanding of the relevant physical phenomena.