Mean creep: the soft mode in elastic sheet buckling

In this note, we introduce the equations for the order parameters describing the buckling of thin, elastic sheets. What is new is the realization that mean creep, namely in-plane displacements, are soft (Goldstone) modes which can be driven by variations in the pattern intensity and which, in turn, affect how the buckling pattern develops. The order-parameter equations are canonical and belong to the universal classes of equations for pattern order parameters to which Yoshiki Kuramoto has contributed so much. We are very pleased to be part of this special issue of Physica D in honoring this remarkable colleague.