Structures of moduli spaces of generalized Cantor sets

Abstract

For each $ω\in (0, 1)^{\mathbb N}$, we may construct a Cantor set $E(ω)\subset [0, 1]$ called a generalized Cantor set for $ω$. We study the moduli space of $ω$ denoted by $\mathcal M(ω)\subset (0, 1)^{\mathbb N}$. It is the set of $ω'$ so that $E(ω')$ is quasiconformally equivalent to $E(ω)$. In this paper, we show that the set $\mathcal M(ω)$ is measurable in $(0, 1)^{\mathbb N}$ and we give a necessary condition for $ω'$ to belong to $\mathcal M(ω)$. By using this condition, we show that there are uncountably many moduli spaces in $(0, 1)^{\mathbb N}$. We also show that except for at most one moduli space, the volume of the moduli space with respect to the standard product measure of $(0, 1)^{\mathbb N}$ vanishes.