Stability of (1+1)-dimensional causal relativistic viscous hydrodynamics

The stability of the (1+1)-dimensional solution of Israel–Stewart theory is investigated. Firstly, the evolution of the temperature and the ratio of the bulk pressure over the equilibrium pressure of the background are explored. Then the stability with linear perturbations is studied by using the Lyapunov direct method. It shows that the shear viscosity may weaken the instability induced by the large peak of bulk viscosity around the phase transition temperature Tc.