English

On highly degenerate CR maps of spheres

Complex Variables 2024-04-29 v1

Abstract

For N4N \geq 4 we classify the (N3)(N-3)-degenerate smooth CR maps of the three-dimensional unit sphere into the (2N1)(2N-1)-dimensional unit sphere. Each of these maps has image being contained in a five-dimensional complex-linear space and is of degree at most two, or equivalent to one of the four maps into the five-dimensional sphere classified by Faran. As a byproduct of our classification we obtain new examples of rational maps of degree three which are (N3)(N-3)-degenerate only along a proper real subvariety and are not equivalent to polynomial maps. In particular, by changing the base point, it is possible to construct new families of nondegenerate maps.

Keywords

Cite

@article{arxiv.2210.13525,
  title  = {On highly degenerate CR maps of spheres},
  author = {Giuseppe della Sala and Bernhard Lamel and Michael Reiter and Duong Ngoc Son},
  journal= {arXiv preprint arXiv:2210.13525},
  year   = {2024}
}