Elliptic and Triangular Flow in Event-by-Event D = 3 + 1 Viscous Hydrodynamics

We present results for the elliptic and triangular flow coefficients ${v}_{2}$ and ${v}_{3}$ in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s}=200\text{ }\text{ }A\mathrm{GeV}$ using event-by-event $\mathrm{D}=3+1$ viscous hydrodynamic simulations. We study the effect of initial state fluctuations and finite viscosities on the flow coefficients ${v}_{2}$ and ${v}_{3}$ as functions of transverse momentum and pseudorapidity. Fluctuations are essential to reproduce the measured centrality dependence of elliptic flow. We argue that simultaneous measurements of ${v}_{2}$ and ${v}_{3}$ can determine $\ensuremath{\eta}/s$ more precisely.