English

Posets uniquely determined by its compact saturated subsets

General Topology 2025-03-05 v1

Abstract

Inspired by Zhao and Xu's study on which a dcpo can be determined by its Scott closed subsets lattice, we further investigate whether a poset (or dcpo) PP is able to be determined by the family Q(P)\mathcal Q(P) of its Scott compact saturated subsets, in the sense that the isomorphism between (Q(P),)(\mathcal Q(P), \supseteq) and (Q(M),)(\mathcal Q(M), \supseteq) implies the isomorphism between PP and MM for any poset (or dcpo) MM, in such case, PP is called Qσ\mathcal Q_{\sigma}-unique. Quasicontinuous domains are proved to be Qσ\mathcal Q_{\sigma}-unique posets and draw support from which, we provide a class of Qσ\mathcal Q_{\sigma}-unique dcpos. We also define a new kind of posets called KDK_D and show that every co-sober KDK_D poset is Qσ\mathcal Q_{\sigma}-unique. It even yields another kind of Qσ\mathcal Q_{\sigma}-unique dcpos. It is gratifying that weakly well-filtered co-sober posets are also Qσ\mathcal Q_{\sigma}-unique. At last, we distinguish among the conditions which make a poset (or dcpo) Qσ\mathcal Q_{\sigma}-unique from each other by some examples; meanwhile, it is confirmed that none of them except the property of being co-sober are necessary for a poset (or dcpo) to be Qσ\mathcal Q_{\sigma}-unique.

Cite

@article{arxiv.2503.02602,
  title  = {Posets uniquely determined by its compact saturated subsets},
  author = {Huijun Hou and Qingguo Li},
  journal= {arXiv preprint arXiv:2503.02602},
  year   = {2025}
}
R2 v1 2026-06-28T22:06:19.587Z