Transient Relativistic Fluid Dynamics in a General Hydrodynamic Frame

We propose a new theory of second-order viscous relativistic hydrodynamics which does not impose any frame conditions on the choice of the hydrodynamic variables. It differs from Mueller-Israel-Stewart theory by including additional transient degrees of freedom, and its first-order truncation reduces to BemficaDisconzi-Noronha-Kovtun theory. Conditions for causality and stability are explicitly given in the conformal regime. As an illustrative example, we consider Bjorken flow solutions to our equations and identify variables which make a hydrodynamic attractor manifest.

Automated summary

This study presents a new theory of second-order viscous relativistic hydrodynamics without imposing frame conditions on the choice of hydrodynamic variables, and explicitly provides conditions for causality and stability in the conformal regime. By considering Bjorken flow solutions, variables that make a hydrodynamic attractor manifest are identified.