On isomorphisms of $\mathcal{C}(K)$ spaces and cardinal invariants of derivatives of $K$

Abstract

We present a necessary condition for a pair of $\mathcal{C}(K)$ spaces to be isomorphic in terms of topological properties of Cantor-Bendixon derivatives of $K$. This in particular gives a completely new information about the perfect kernels of such $K$. In the process, we extend known lower estimates of the Banach-Mazur distance between a pair of spaces of continuous functions from the case of scattered compact spaces to a more general setting. Next, we apply this general result to deduce some new information about isomorphisms of spaces of continuous functions over Eberlein compacta of height $\omega +1$. Further, we show that isomorphisms of $\mathcal{C}(K)$ spaces preserve the spread of $K$, and we also prove some new results for pairs of spaces of continuous functions whose Banach-Mazur distance is less than $3$.