ZFC construction of separable scattered compact spaces without smooth renormings

Construct, in ZFC, a compact, scattered, separable space K such that C(K) admits no equivalent Fréchet smooth norm; additionally determine whether K can be chosen so that C(K) has the renorming-stable ball-covering property, and whether the conclusion can be strengthened by replacing Fréchet smoothness with Gâteaux smoothness.

Background

The paper gives examples of compact separable scattered spaces K for which C(K) has the renorming-stable ball-covering property (RBCP) but lacks an equivalent norm with strictly convex dual. It also presents, consistently under a forcing model, a compact separable scattered space whose C(K) has the RBCP but admits no equivalent Fréchet smooth norm. The authors ask whether a corresponding example exists in ZFC, and whether the same phenomenon can be obtained for Gâteaux smooth renormings.

The problem is motivated by the contrast with Haydon’s ZFC example of a non-separable scattered compact space whose C(K) admits neither an equivalent strictly convex norm nor an equivalent Gâteaux smooth norm, together with the obstruction that separable compactifications of omega have w*-separable duals and therefore admit equivalent strictly convex norms. The RBCP requirement would connect the renorming obstruction to the central ball-covering property studied in the paper.

References

Does there exist, in ZFC, a compact, scattered and separable space $K$ such that $C(K)$ admits no equivalent Fréchet smooth norm? If so, can we also ensure that $C(K)$ has the RBCP? Can we go further and replace Fréchet smooth above by Gâteaux smooth?

— The renorming-stable ball covering property and $C(K)$-spaces  (2610.05846 - Liu et al., 5 Oct 2026) in Section Problems and remarks, first displayed Problem

However, we were unable to establish whether or not $C(K)$ has the RBCP whenever $K$ is scattered and separable. This prompts our second problem, which is connected to the first.

Let $K$ be compact, scattered and separable. Does $C(K)$ have the RBCP?

— The renorming-stable ball covering property and $C(K)$-spaces  (2610.05846 - Liu et al., 5 Oct 2026) in Section Problems and remarks, second displayed Problem