Skip to main content
2 of 3
added 44 characters in body
Santi Spadaro
  • 4.4k
  • 31
  • 40

A space with independent tightness

Recall that the tightness of a topological space $X$ is defined as the least cardinal $\kappa$ such that for every non-closed subset $A$ of $X$ and every point $x \in \overline{A} \setminus A$, there is a set $B \subset A$ such that $|B| \leq \kappa$ and $x \in \overline{B}$.

QUESTION: Is there a ZFC example of a space which is countably tight in some model of ZFC and uncountably tight in some other model?

Santi Spadaro
  • 4.4k
  • 31
  • 40