English

Cantor sets with high-dimensional projections

Geometric Topology 2022-12-07 v1 General Topology

Abstract

In 1994, J.Cobb constructed a tame Cantor set in R3\mathbb R^3 each of whose projections into 22-planes is one-dimensional. We show that an Antoine's necklace can serve as an example of a Cantor set all of whose projections are one-dimensional and connected. We prove that each Cantor set in Rn\mathbb R^n, n3n\geqslant 3, can be moved by a small ambient isotopy so that the projection of the resulting Cantor set into each (n1)(n-1)-plane is (n2)(n-2)-dimensional. We show that if XRnX\subset \mathbb R^n, n2n\geqslant 2, is a zero-dimensional compactum whose projection into some plane ΠRn\Pi\subset \mathbb R^n with dimΠ{1,2,n2,n1}\dim \Pi \in \{1, 2, n-2, n-1\} is zero-dimensional, then XX is tame; this extends some particular cases of the results of D.R.McMillan, Jr. (1964) and D.G.Wright, J.J.Walsh (1982). We use the technique of defining sequences which comes back to Louis Antoine.

Cite

@article{arxiv.2212.02984,
  title  = {Cantor sets with high-dimensional projections},
  author = {Olga Frolkina},
  journal= {arXiv preprint arXiv:2212.02984},
  year   = {2022}
}
R2 v1 2026-06-28T07:23:35.506Z