Special Session 51: Phase field models and real world applications

Gradient stability of high order BDF methods and some applications

Morgan Pierre
Universite de Poitiers
France
Co-Author(s):    Anass Bouchriti and Noureddine Alaa
Abstract:
It is well known that the Allen-Cahn equation is a gradient flow. In 1993, Elliott and Stuart proved that the k-step backward differentiation formula (BDFk) applied to the Allen-Cahn equation preserves its gradient structure for k=1, 2 and 3, if the time step is small enough. In 1996, Stuart and Humphries generalized this result for the BDFk method applied to the gradient flow of a semiconvex function and they left open the question for k=4, 5 and 6. In this talk, we show that the BDF4 and BDF5 schemes are gradient stable and we give a negative answer to the question for the BDF6 scheme. We also give some applications of these results to the Allen-Cahn and Cahn-Hilliard equations.