Uniqueness and nonuniqueness of fronts for degenerate diffusion-convection reaction equations

Abstract

We consider a scalar parabolic equation in one spatial dimension. The equation is constituted by a convective term, a reaction term with one or two equilibria, and a positive diffusivity which can however vanish. We prove the existence and several properties of traveling-wave solutions to such an equation. In particular, we provide a sharp estimate for the minimal speed of the profiles and improve previous results about the regularity of wavefronts. Moreover, we show the existence of an infinite number of semi-wavefronts with the same speed.

Keywords

• degenerate and doubly degenerate diffusivity
• diffusion-convection-reaction equations
• traveling-wave solutions
• sharp profiles
• semi-wavefronts