English

On generic topological embeddings

General Topology 2024-07-09 v2

Abstract

We show that an embedding of a fixed 0-dimensional compact space KK into the \v{C}ech--Stone remainder ω\omega^* as a nowhere dense P-set is the unique generic limit, a special object in the category consisting of all continuous maps from KK to compact metric spaces. Using Fra\"iss\'e theory we get a few well know theorems about \v{C}ech--Stone remainder. We establish the following: -- an ultrametric space KK of weight κ\kappa can be uniformly embedded into κκ\kappa^\kappa as a uniformly nowhere dense subset, -- every uniform homeomorphism of uniformly nowhere dense sets in κκ\kappa^\kappa can be extended to a uniform auto-homeomorphism of κκ\kappa^\kappa, -- every uniformly nowhere dense set in κκ\kappa^\kappa is a uniform retract of κκ\kappa^\kappa. If we assume that κ\kappa is a weakly compact cardinal we get the counterpart of the above result without the uniformity assumption.

Keywords

Cite

@article{arxiv.2310.05043,
  title  = {On generic topological embeddings},
  author = {Wiesław Kubiś and Andrzej Kucharski and Sławomir Turek},
  journal= {arXiv preprint arXiv:2310.05043},
  year   = {2024}
}
R2 v1 2026-06-28T12:43:43.863Z