English

A note on $\delta$-strongly compact cardinals

Logic 2020-09-25 v4 General Topology

Abstract

In this paper we investigate more characterizations and applications of δ\delta-strongly compact cardinals. We show that, for a cardinal κ\kappa the following are equivalent: (1) κ\kappa is δ\delta-strongly compact, (2) For every regular λκ\lambda \ge \kappa there is a δ\delta-complete uniform ultrafilter over λ\lambda, and (3) Every product space of δ\delta-Lindel\"of spaces is κ\kappa-Lindel\"of. We also prove that in the Cohen forcing extension, the least ω1\omega_1-strongly compact cardinal is a precise upper bound on the tightness of the products of two countably tight spaces.

Keywords

Cite

@article{arxiv.2001.02124,
  title  = {A note on $\delta$-strongly compact cardinals},
  author = {Toshimichi Usuba},
  journal= {arXiv preprint arXiv:2001.02124},
  year   = {2020}
}

Comments

arXiv admin note: text overlap with arXiv:1709.07991

R2 v1 2026-06-23T13:05:08.212Z