Dr. Marcelo Disconzi, Vanderbilt University
 

We will discuss some recent results concerning mathematical aspects of relativistic fluids, focusing on the evolution problem for Einstein’s equations coupled to the equations of relativistic fluid dynamics and the role played by the underlying geometry. Einstein’s equations are a system of geometric evolution equations, but the geometric aspects we would like to emphasize come from the fluid part. We will discuss the importance of the boundary geometry in the description of free-boundary relativistic fluids; the Lorentzian geometry hidden behind the propagation of sound waves in relativistic perfect fluids and how it reveals a remarkable null-structure of the equations; and the geometry of the characteristics in relativistic fluids with viscosity.