Structure of the parameter space of the Hénon map.

The parameter space of the Henon map is reported to contain a regular structure-parallel-to-structure sequence of shrimp-shaped robust isoperiodic domains. They appear densely concentrated on a neighborhood along a main α direction, extending across both orientation-preserving and -reversing domains. There is also a secondary β direction, roughly perpendicular to a very dense «foliation of legs» emanating from the isoperiodic domains. Familiar bifurcation phenomena observed in unimodal maps correspond to particular cuts along the β direction. The α direction is rich in new phenomena. The topology along α is conjectured to be typical of bimodal maps