Colloquium
DATE	2022-11-03　16:10-17:00
PLACE	數學系館 1F3174教室
SPEAKER	戴佳原 教授（國立中興大學應用數學系）
TITLE	Pattern-Selective Feedback Stabilization of Ginzburg-Landau Spiral Waves
ABSTRACT	The complex Ginzburg–Landau equation serves as a paradigm of pattern formation and the existence and stability properties of Ginzburg–Landau m-armed spiral waves have been investigated extensively. However, many multi-armed spiral waves are unstable and thereby rarely visible in experiments and numerical simulations. In this talk we explain how to selectively stabilize certain significant classes of unstable spiral waves within circular and spherical geometries. As a result, stable spiral waves with an arbitrary number of arms are obtained for the first time. Our tool for stabilization is the symmetry-breaking control triple method, which is an equivariant generalization of the widely applied Pyragas control to the setting of PDEs. This is a joint work with I. Schneider and B. de Wolff (reference: Arch. Ration. Mech. Anal., 246(1), (2022). Open Access: https://rdcu.be/cXDEm.