Asymptotic L-p stability for transition fronts in Cahn-Hilliard systems

We consider the asymptotic behavior of perturbations of transition front solutions arising in Cahn-Hilliard systems on R. Such equations arise naturally in the study of phase separation processes, and systems describe cases in which three or more phases are possible. When a Cahn-Hilliard system is linearized about a transition front solution, the linearized operator has an eigenvalue at 0 (due to shift invariance), which is not separated from essential spectrum. In cases such as this, nonlinear stability cannot be concluded from classical semigroup considerations and a more refined development is appropriate. Our main result asserts that if initial perturbations are small in L-1 boolean AND L-infinity then spectral stability-a necessary condition for stability, defined in terms of an appropriate Evans function implies asymptotic nonlinear stability in LP for all 1 <p <= infinity.close1