Sobriety of the Scott space of the rational line
Determine whether the Scott space of the lattice of open subsets of the rational line \(\mathbb{Q}\) is sober, equivalently, whether the Hoare power space \(H(\mathbb{Q})\) is co-sober.
References
He and Zhao also asked whether $\SigmaO(\mathbb{Q})$ is sober for the rational line $\mathbb{Q}$. The construction above does not decide that more specific question. By Theorem~\ref{thm:bridge}, it is equivalent to asking whether $H(\mathbb{Q})$ is co-sober.
— A countable metric space whose Hoare power space is not co-sober
(2610.05868 - Xu et al., 5 Oct 2026) in Section 5, Concluding remarks