Holography, also known as AdS/CFT correspondence, is a duality which maps the physics of a strongly coupled quantum field configuration onto the physics of a weakly curved model spacetime. Due to its applicability for strongly coupled dense systems, it is a powerful method in the context of heavy-ion collisions.
The quark-gluon plasma in heavy-ion collisions is produced far from equilibrium. While the influence of spatial gradients on this strongly coupled deconfined system already receives high attention, the impact of strong temporal gradients deserves more investigation. The specific shear viscosity η/s is a key parameter for the description of the quark-gluon plasma. We extend the notion of shear transport and entropy density to the far-from-equilibrium regime and investigate the time dependence of η/s in a holographic model. For typical LHC collisions, we find strong deviations by more than 60%. The inclusion of this effect may have considerable relevance for the analysis of heavy-ion collision data and for our understanding of the deconfined phase of QCD.