English

Extending Isotopies of Planar Continua

Geometric Topology 2008-11-04 v1

Abstract

In this paper we solve the following problem in the affirmative: Let ZZ be a continuum in the plane \complex\complex and suppose that h:Z×[0,1]\complexh:Z\times [0,1]\to\complex is an isotopy starting at the identity. Can hh be extended to an isotopy of the plane? We will provide a new characterization of an accessible point in a planar continuum ZZ and use it to show that an accessible point is preserved during the isotopy. We show next that the isotopy can be extended over hyperbolic crosscuts. The proof makes use of the notion of a metric external ray, which mimics the notion of a conformal external ray, but is easier to control during an isotopy.

Keywords

Cite

@article{arxiv.0811.0364,
  title  = {Extending Isotopies of Planar Continua},
  author = {Lex G. Oversteegen and E. D. Tymchatyn},
  journal= {arXiv preprint arXiv:0811.0364},
  year   = {2008}
}

Comments

23 pages, 1 figure