On the geometry of folded cuspidal edges
arXiv:1706.02074
Abstract
We study the geometry of cuspidal singularities in obtained by folding generically a cuspidal edge. In particular we study the geometry of the cuspidal cross-cap , i.e. the cuspidal singularity. We study geometrical invariants associated to and show that they determine it up to order 5. We then study the flat geometry (contact with planes) of a generic cuspidal cross-cap by classifying submersions which preserve it and relate the singularities of the resulting height functions with the geometric invariants.
Second version generalizes some results for all cuspidal singularities, not only the cuspidal cross-cap