On the well-posedness of relativistic viscous fluids with non-zero   vorticity
  We study the problem of coupling Einstein's equations to a relativistic and physically well-motivated version of the Navier-Stokes equations. Under a natural evolution condition for the vorticity, we prove existence and uniqueness in a suitable Gevrey class if the fluid is incompressible, where this condition is given an appropriate relativistic interpretation, and show that the solutions enjoy the finite propagation speed property. 
Magdalena Czubak, Marcelo M. Disconzi
math-ph gr-qc math.AP math.DG math.MP