Hopf Bifurcation from Fronts in the Cahn–Hilliard Equation

We study Hopf bifurcation from traveling-front solutions in the Cahn–Hilliard equation. The primary front is induced by a moving source term. Models of this form have been used to study a variety of physical phenomena, including pattern formation in chemical deposition and precipitation processes. Technically, we study bifurcation in the presence of an essential spectrum. We contribute a simple and direct functional analytic method and determine bifurcation coefficients explicitly. Our approach uses exponential weights to recover Fredholm properties and spectral flow ideas to compute Fredholm indices. Simple mass conservation helps compensate for negative indices. We also construct an explicit, prototypical example, prove the existence of a bifurcating front, and determine the direction of bifurcation.