Speaker
Description
Far-from-equilibrium quantum many-body systems can exhibit universal behavior long before reaching thermal equilibrium. A prominent example is provided by Nonthermal Fixed Points, attractive dynamical regimes characterized by self-similar evolution that have been predicted in contexts ranging from early-universe cosmology to heavy-ion collisions and observed in ultracold-atom experiments.
Our current understanding of Nonthermal Fixed Points is largely restricted to spatially homogeneous systems. Recently, it has been suggested that spatial inhomogeneities around these states may lead to the emergence of fluid-like dynamics. In this talk, I will show how Nonthermal Fixed Points in expanding systems can be understood as ideal hydrodynamic realizations of their non-expanding counterparts. Focusing on Bjorken flow, a longitudinally expanding system relevant for heavy-ion collisions, I will further demonstrate how the expansion-induced inhomogeneity gives rise to second-order hydrodynamic behavior. These results establish a direct connection between Nonthermal Fixed Points and far-from-equilibrium hydrodynamics.