date: jeudi 6 avril, 16h30 lieu : Calais, salle B014 intervenant: D. Shepelsky, Institute of Low Temperatures, Kharkiv, Ukraine Titre : Matrix Baker-Akhiezer function on the complex plane with cuts Résumé : We give a new definition and representation of a matrix Baker-Akhiezer function on the complex plane with cuts, which generates finite-genus (quasi periodic) solutions of the nonlinear Schroedinger equation. Such a representation can be efficiently used for different applications in the theory of integrable nonlinear equations, particularly, for studying the initial value problems with "step-like" initial data.