Divergence-type nonlinear conformal hydrodynamics

Understand

Within the theoretical framework of divergence-type theories (DTTs), we set up a consistent nonlinear hydrodynamical description of a conformal fluid in flat space-time.

• DTTs go beyond second-order (in velocity gradients) theories, and are closed in the sense that they do not rely on adiabatic expansions.
• We show that the stress-energy tensor constructed from second-order conformal invariants is obtained from the DTT by a consistent adiabatic expansion.
• The DTT satisfies the Second Law, and is causal in a set of fluid states near equilibrium.