Symmetric cumulants and event-plane correlations in Pb + Pb collisions

The ALICE Collaboration has recently measured the correlations between amplitudes of anisotropic flow in different Fourier harmonics, referred to as symmetric cumulants. We derive approximate relations between symmetric cumulants involving v4 and v5 and the event-plane correlations measured by the ATLAS Collaboration. The validity of these relations is tested using event-by-event hydrodynamic calculations. The corresponding results are in better agreement with the ALICE data than existing hydrodynamic predictions. We make quantitative predictions for three symmetric cumulants which have not yet been measured.