Waiting time phenomena for degenerate parabolic equations - A unifying approach

We present a new approach to establish the occurrence of waiting time phenomena for solutions to degenerate parabolic equations. Originally developed by the authors for the thin film equation, it may in fact be used for a broad class of degenerate parabolic equations and systems having divergence structure, such as doubly nonlinear second order equations of porous media type as well as higher order doubly nonlinear equations with variational structure.