Diffusion–convection reaction equations with sign-changing diffusivity and bistable reaction term

We consider a reaction–diffusion equation with convection term in one space variable, where the diffusion changes sign from positive to negative and reaction is bistable. study existence of wavefront solutions, their uniqueness regularity. The presence reveals several new features wavefronts: according mutual positions diffusivity reaction, profiles can occur either for single value speed or bounded interval such values; (up shifts) lost; moreover, plateaus arbitrary length appear; be singular vanishes.