Description
General-covariant Galilean or Carrollian hydrodynamics can be reached from relativistic fluids observed from either Zermelo or Randers-Papapetrou frames, at infinite or vanishing velocity of light. I will focus on the latter case, display the general equations and describe the paramount role of Carrollian fluids in flat holography: duals of Ricci-flat spacetimes in the sense of fluid/gravity correspondence are Carrollian fluids defined at null infinity. Robinson-Trautman or Kerr-Taub-NUT families illustrate these results.
