English

Submaximal spaces and cardinal invariants

General Topology 2021-12-08 v1 Logic

Abstract

We give a combinatorial characterization of countable submaximal subspaces of 2κ2^\kappa. Using a parametrized version of Mathias forcing, we prove that there exists a countable submaximal subspace of 2ω12^{\omega_1} whilst c=ω2\mathfrak{c}=\omega_2. Combining this with previous results, we construct a disjointly tight countable irresolvable space of weight <c<\mathfrak{c}, answering a question of Bella and Hru\v{s}\'{a}k.

Keywords

Cite

@article{arxiv.2112.03447,
  title  = {Submaximal spaces and cardinal invariants},
  author = {César Corral},
  journal= {arXiv preprint arXiv:2112.03447},
  year   = {2021}
}

Comments

11 pages

R2 v1 2026-06-24T08:06:57.540Z