NoteNon-extinction of solutions to a fast diffusive p-Laplace equation with Neumann boundary conditions

In this note, the authors establish a non-extinction result for the changing sign solution with negative initial energy by discussing a suitable differential inequality. The result gives an answer to the problem unsolved in Qu, Bai, Zheng (2014) [1]. Two examples are given in the paper to show the existence of the initial datum with negative initial energy.