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An Embedding, An Extension, and An Interpolation of Ultrametrics\(^*\)

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Abstract

The notion of ultrametrics can be considered as a zero-dimensional analogue of ordinary metrics, and it is expected to prove ultrametric versions of theorems on metric spaces. In this paper, we provide ultrametric versions of the Arens-Eells isometric embedding theorem of metric spaces, the Hausdorff extension theorem of metrics, the Niemytzki-Tychonoff characterization theorem of the compactness, and the author’s interpolation theorem of metrics and theorems on dense subsets of spaces of metrics.

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Acknowledgments

The author would like to thank Professor Koichi Nagano for his advice and constant encouragement. The author would also like to thank the referee for helpful comments and suggestions.

Funding

The author was supported by JSPS KAKENHI Grant Number 18J21300.

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Correspondence to Yoshito Ishiki.

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Ishiki, Y. An Embedding, An Extension, and An Interpolation of Ultrametrics\(^*\). P-Adic Num Ultrametr Anal Appl 13, 117–147 (2021). https://doi.org/10.1134/S2070046621020023

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  • DOI: https://doi.org/10.1134/S2070046621020023

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