Lecture 11 - Tue 2020 10 06 - Virtual % ============================================================================== (1-2) are from Lecture 9 (1) Example of a conservative system: double well and pendulum. (2) Introduce/define reversible system [invariance t to -t and y to -y]. Theorem: For reversible systems, linear centers stay centers. (3) Index theory: Definition of index [need isolated critical point]. Example for Saddle Point [-1]. Properties of the index. (4) Cycle graphs. Example via homoclynic connections [e.g.: as in (1)] More complicated examples [pictorial]. % % ============================================================================== % % ============================================================================== EOF