Hydrodynamic attractor in the non-conformal Bjorken flow

Understand

Non-conformal attractor behavior is studied by solving non-conformal second order viscous hydrodynamics with respect to boost-invariant plasmas.

• Numerical solutions of the relative decay rate of the enthalpy density, the inverse shear and bulk Reynolds numbers, all exhibit universal patterns towards an ideal fluid description at late stages, demonstrating the existence of non-conformal hydrodynamic attractor.
• However, as a generic feature, the non-conformal hydrodynamic attractor emerges only at late times, which differs drastically from the behavior observed in conformal systems.
• The absence of the early-time attractor in non-conformal fluids is a consequence of the early-time instable mode, which arises from a positive-valued eigen-mode associated with the free-streaming dynamics.