A singularity theory analysis of bifurcation problems with octahedral symmetry
Melbourne, Ian; Melbourne, Ian; Mathematics Institute, University of Warwick
Журнал:
Dynamics and Stability of Systems
Дата:
1986
Аннотация:
We analyse bifurcation problems with octahedral symmetry using results from singularity theory. For non-degenerate bifurcation problems equivariant with respect to the standard action of the octahedral group on we find three branches of symmetry-breaking bifurcation corresponding to the three maximal isotropy subgroups of the symmetry group with one-dimensional fixed-point subspaces. Locally, one of these branches is never asymptotically stable, but precisely one of the other branches is stable if and only if all three branches bifurcate supercritically.A singularity theory classification of these non-degenerate bifurcation problems yields two normal forms. One of these normal forms is of topological codimension one, and so a non-degenerate bifurcation problem need not be generic. Also, each normal form comprises a modal family. Hence the singularity theory classification is more delicate than a topological analysis. In particular, the modal parameters partition the space of non-degenerate bifurcation problems first according to branching and stability considerations as would be expected in a topological classification, but do not stop there. We discuss geometric interpretations of the delicate features of the singularity theory analysis. A recent result of Gaffney about high-order terms is used to simplify calculations. Further simplifications arise from a connectedness result. In particular, we do not have to consider an explicit change of coordinates.
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