English

On closed embeddings in $P^N \cup Q^N$

General Topology 2025-03-25 v1

Abstract

We prove that if a separable metrizable XX is a union of two disjoint 0-dimensional sets EE, FF, EE is absolutely GδG_{\delta} and FF is absolutely FσδF_{\sigma\delta} then there is a closed embedding hh into the union of countable products of the irrationals and the rationals with EE being the preimage under hh of the countable product of the irrationals and FF being the preimage under hh of the countable product of the rationals. We prove also that for the set HH of points xx in the Hilbert cube such that for each kk there is ll with x(2k3l)=0x(2^k 3^l)=0, whenever AA is an FσδF_{\sigma \delta} set in a compact one-dimensional space XX, there is an embedding hh into the union of the countable product of the irrationals with added point 00, and the countable product of the rationals, such that AA is the preimage under hh of the set HH.

Keywords

Cite

@article{arxiv.2503.17892,
  title  = {On closed embeddings in $P^N \cup Q^N$},
  author = {Elżbieta Pol and Roman Pol and Mirosława Reńska},
  journal= {arXiv preprint arXiv:2503.17892},
  year   = {2025}
}
R2 v1 2026-06-28T22:31:04.646Z