Special Session 21: Evolution Equations and Integrable Systems

Initial-boundary value problems for evolution equations via the Fokas method

Alex Himonas
University of Notre Dame
USA
Co-Author(s):    
Abstract:
The Fokas unified transform method provides a novel approach for solving initial-boundary value problems (ibvp's) for linear and integrable nonlinear partial differential equations. In particular, it gives solution formulas for forced linear ibvp's. Using these formulas Fokas and collaborators initiated a new approach for studying the well-posedness in Sobolev spaces of ibvp's for nonlinear evolution equations, which is analogous to the way well-posedness of initial value problems (ivp's) are studied based on the Fourier method. Utilizing the Fokas solution formulas linear estimates are derived, and then using the multilinear estimates suggested by the nonlinearity it is shown that the iteration map defined by this formula is a contraction in appropriate solution spaces. In this talk we will present key points of this approach for the Korteweg-de Vries, the nonlinear Schr\"odinger and related equations and systems. The talk is based on collaborative work with A. Fokas, D. Mantzavinos and F. Yan.