Simultaneous extensions of metrics and ultrametrics of high power

Abstract

In this paper, generalized metrics mean metrics taking values in general linearly ordered Abelian groups. Using the Hahn fields, we first prove that for every generalized metric space, if the set of the Archimedean equivalence classes of the range group of the metric has an infinite decreasing sequence, then every nonempty closed subset of the space is a uniform retract of the ambient space. Next we construct simultaneous extensions of generalized metrics and ultrametrics. From the existence of extensors of generalized metrics, we characterize the final compactness of generalized metrizable spaces using the completeness of generalized metrics. Contents 1. Introduction 1 2. Preliminaries 11 3. Retractions 28 4. Extensors of ultrametrics and metrics of high power 32 5. Table of symbols 39 References 41