This three-year award provides support for US-France cooperative research on mathematical problems in continuum modeling and analysis for physical systems. The collaboration involves the US research team led by Gui-Qiang Chen at the Northwestern University and the French team led by Michel Rascle at the Mathematics Laboratory of the University of Nice. The investigators will study compressible Euler equations, entropy flux splittings, kinetic formulations, microstructure, phase transition and metastability. The underlying mathematical theme is that of singular limits; the unifying physical theme is that of continuum mechanics. The project takes advantage of the complementary expertise of the US and French investigators and will advance understanding of mathematical underpinnings of problems in physical systems.