"Anomalous Viscosity of an Expanding Quark-Gluon Plasma"

We argue that an expanding quark-gluon plasma has an anomalous viscosity, which arises from interactions with color fields dynamically generated by the Weibel instability. We derive an expression for the anomalous viscosity in the turbulent plasma domain and apply it to the hydrodynamic expansion phase, when the quark-gluon plasma is near equilibrium. The anomalous viscosity dominates over the collisional viscosity for weak coupling. This effect may provide an explanation for the apparent nearly perfect liquidity of the matter produced in nuclear collisions at RHIC without the assumption that it is a strongly coupled state and that the collisional viscosity dominates the total viscosity.