Causality and stability of relativistic spin hydrodynamics

Theories of Relativistic Dissipative Fluid Dynamics

“…There have been numerous works deriving the additional equations needed from the entropy principle [ 214 , 215 , 216 ], Zubarev’s non-equilibrium statistical operator [ 217 , 218 ], Lagrangian hydrodynamics [ 219 , 220 ], Chapman–Enskog theory [ 221 ], coupling to torsion [ 222 , 223 , 224 ], and kinetic theory [ 87 , 122 , 123 , 127 , 156 , 225 , 226 , 227 , 228 ]. The linear stability of spin hydrodynamics has been addressed in [ 87 , 229 , 230 ], and steps towards spin hydrodynamics in the presence of electromagnetic fields have been undertaken in [ 231 , 232 , 233 ]. While a full account of the various formulations of spin hydrodynamics as described above is outside the scope of this work, we will outline the most salient features when considering a formulation based on quantum kinetic theory, which is similar to the procedures discussed in Section 5 .…”