English

A guessing principle from a Souslin tree, with applications to topology

Logic 2021-09-30 v2 General Topology

Abstract

We introduce a new combinatorial principle which we call AD\clubsuit_{AD}. This principle asserts the existence of a certain multi-ladder system with guessing and almost-disjointness features, and is shown to be sufficient for carrying out de Caux type constructions of topological spaces. Our main result states that strong instances of AD\clubsuit_{AD} follow from the existence of a Souslin tree. It is also shown that the weakest instance of AD\clubsuit_{AD} does not follow from the existence of an almost Souslin tree. As an application, we obtain a simple, de Caux type proof of Rudin's result that if there is a Souslin tree, then there is an SS-space which is Dowker.

Keywords

Cite

@article{arxiv.2104.09150,
  title  = {A guessing principle from a Souslin tree, with applications to topology},
  author = {Assaf Rinot and Roy Shalev},
  journal= {arXiv preprint arXiv:2104.09150},
  year   = {2021}
}

Comments

Final version. To appear at the Kunen special issue of Top. Appl