English

The Stone-Cech compactifications of $\omega^*\setminus \{x\}$ and $S_\kappa\setminus\{x\}$

General Topology 2014-06-02 v3

Abstract

The space SκS_\kappa is the Stone space of the κ\kappa-saturated Boolean algebra of cardinality κ\kappa. It exists provided that κ=κ<κ\kappa = \kappa^{<\kappa}, and is characterised topologically as the unique κ\kappa-Parovichenko space of weight κ\kappa. Under the Continuum Hypothesis, Sω1S_{\omega_1} coincides with ω\omega^*. This paper investigates questions related to the Stone-Cech compactification of spaces Sκ{x}S_\kappa \setminus \{x\}, extending corresponding results obtained by Fine & Gillman and Comfort & Negrepontis for the space ω\omega^*. We show that for every point xx of SκS_\kappa, the Stone-Cech remainder of Sκ{x}S_\kappa \setminus \{x\} is a κ+\kappa^+-Parovichenko space of cardinality 22κ2^{2^\kappa} which admits a family of 2κ2^\kappa disjoint clopen sets. As a corollary we get that it is consistent with CH that the Stone-Cech remainders of ω{x}\omega^* \setminus \{x\} are all homeomorphic.

Keywords

Cite

@article{arxiv.1310.0678,
  title  = {The Stone-Cech compactifications of $\omega^*\setminus \{x\}$ and $S_\kappa\setminus\{x\}$},
  author = {Max F. Pitz and Rolf Suabedissen},
  journal= {arXiv preprint arXiv:1310.0678},
  year   = {2014}
}

Comments

18 pages. V3: Extended version; Thm 6.3 proves an open conjecture from V2