2000 character limit reached
A counterexample related to a theorem of Komjath and Weiss (2307.00602v1)
Published 2 Jul 2023 in math.LO and math.GN
Abstract: In a paper from 1987, Komjath and Weiss proved that for every regular topological space $X$ of character less than $\mathfrak b$, if $X\rightarrow(top~\omega+1)1_\omega$, then $X\rightarrow(top~\alpha)1_\omega$ for all $\alpha<\omega_1$. In addition, assuming $\diamondsuit$, they constructed a space $X$ of size continuum, of character $\mathfrak b$, satisfying $X\rightarrow(top~\omega+1)1_\omega$, but not $X\rightarrow(top~\omega2+1)1_\omega$. Here, a counterexample space with the same characteristics is obtained outright in ZFC.
Sponsored by Paperpile, the PDF & BibTeX manager trusted by top AI labs.
Get 30 days freePaper Prompts
Sign up for free to create and run prompts on this paper using GPT-5.
Top Community Prompts
Collections
Sign up for free to add this paper to one or more collections.