English

Tie-points and fixed-points in N^*

Logic 2007-11-21 v1 General Topology

Abstract

A point x is a (bow) tie-point of a space X if X setminus {x} can be partitioned into (relatively) clopen sets each with x in its closure. Tie-points have appeared in the construction of non-trivial autohomeomorphisms of betaN setminus N and in the recent study of (precisely) 2-to-1 maps on betaN setminus N . In these cases the tie-points have been the unique fixed point of an involution on betaN setminus N. This paper is motivated by the search for 2-to-1 maps and obtaining tie-points of strikingly differing characteristics.

Keywords

Cite

@article{arxiv.0711.3037,
  title  = {Tie-points and fixed-points in N^*},
  author = {Alan Dow and Saharon Shelah},
  journal= {arXiv preprint arXiv:0711.3037},
  year   = {2007}
}
R2 v1 2026-06-21T09:45:05.234Z