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Article

Keywords:
Stone-Čech compactification; ultrametric space; corona; Higson's corona; space of ends
Summary:
We show that, under CH, the corona of a countable ultrametric space is homeomorphic to $\omega^*$. As a corollary, we get the same statements for the Higson's corona of a proper ultrametric space and the space of ends of a countable locally finite group.
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