English

Madness and (weak) normality

General Topology 2021-05-12 v3

Abstract

We consider weakenings of normality in Ψ\Psi-spaces and prove that the existence of a MAD family whose Ψ\Psi-space is almost-normal is independent of \textsf{ZFC}. We also construct a partly-normal not quasi-normal AD family, answering questions from Garc\'ia-Balan and Szeptycki. We finish by showing that the concepts of almost-normal and strongly 0\aleph_0-separated AD families are different, even under \textsf{CH}, answering a question from Oliveira-Rodrigues and Santos-Ronchim

Cite

@article{arxiv.2101.01829,
  title  = {Madness and (weak) normality},
  author = {César Corral},
  journal= {arXiv preprint arXiv:2101.01829},
  year   = {2021}
}

Comments

19 pages

R2 v1 2026-06-23T21:49:21.789Z