Non-equilibrium dynamics of Goldstone excitation from holography

By using the holographic approach, we investigate the interplay between the order parameter and Goldstone modes in the real-time dynamics of the chiral phase transition. By quenching the system to a different thermal bath and obtaining different kinds of initial states, we solve the real-time evolution of the system numerically. Our main focus is on studying far-from equilibrium dynamics of strongly-coupled system and universal scaling behaviors related to such dynamics. The most striking observation is that an additional prethermalization stage emerges at non-critical temperature after introducing the Goldstone modes, which is not reported in any previous studies. Some basic properties related to this additional prethermalization stage have been discussed in detail. More interestingly, we also report a new scaling relation describing non-equilibrium evolution at non-critical temperature. This additional universal behavior indicates the appearance of a non-thermal fixed point in the dynamical region.