NONMONOTONIC TWIST MAPS

摘要

We investigate a family of nonmonotonic radial twist maps constructed by unfolding the linear twist function. We find several new modes of reconnection and derive conditions for them to occur. Reconnection and bifurcation of higher order resonances are studied in detail, including vortex pairs and triplets. The structural instability of some of these exotic figures is mitigated by the presence of chaotic separatrix layers. Invariant curves of involution pairs are utilized to locate and chart their often very complex metamorphoses. [References: 23]