A counterexample related to a theorem of Komjath and Weiss
Abstract
In a paper from 1987, Komjath and Weiss proved that for every regular topological space X of character less than b, if X→(top~ω+1)1ω, then X→(top~α)1ω for all α<ω1. In addition, assuming , they constructed a space X of size continuum, of character b, satisfying X→(top~ω+1)1ω, but not X→(top~ω2+1)1ω. Here, a counterexample space with the same characteristics is obtained outright in ZFC.
0
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.