Event-plane correlations and hydrodynamic simulations of heavy ion collisions

We use a nonlinear response formalism to describe the Event-plane correlations measured by the ATLAS Collaboration. With one exception (cos(2Ψ2-6Ψ3+4Ψ4)), the Event-plane correlations are qualitatively reproduced by considering the linear and quadratic response to the lowest cumulants. For the lowest harmonics such as cos(2Ψ2+3Ψ3-5Ψ5), the correlations are quantitatively reproduced, even when the naive Glauber model prediction has the wrong sign relative to experiment. The quantitative agreement for the higher plane correlations (especially those involving Ψ6) is not as good. The centrality dependence of the correlations is naturally explained as an average of the linear and quadratic response.