Sharp, Smooth, and Oscillatory Traveling Waves of Degenerate Diffusion Equation with Delay

Abstract

We consider the non-monotone degenerate diffusion equation with time delay. Different from the linear diffusion equation, the degenerate equation allows for semi-compactly supported traveling waves. In particular, we discover sharp-oscillating waves with sharp edges and non-decaying oscillations. The degenerate diffusion and the effect of time delay cause us essential difficulties. We show the existence for both sharp and smooth traveling wave solutions. Furthermore, we prove the oscillating properties of the waves for large wave speeds and large time delay. Since the existing approaches are not applicable, we develop a new technique to show the existence of the sharp, smooth and oscillatory traveling waves.