The "minimal" viscosity and elliptic flow at RHIC

We show from covariant transport theory that, for a massless ideal gas equation of state, even a small shear viscosity to entropy density ratio $\eta \approx s/(4 \pi)$ generates significant 15-30% dissipative corrections to elliptic flow for conditions expected in mid-peripheral (b = 8 fm) Au+Au collisions at $\sqrt{s_{NN}} \sim 200$ GeV at RHIC.