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On the extension of Hölder maps with values in spaces of continuous functions

Gilles Lancien·Beata Randrianantoanina
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Abstract

We study the isometric extension problem for Hölder maps from subsets of any Banach space into $c_0$ or into a space of continuous functions. For a Banach space $X$, we prove that any $α$-Hölder map, with $0<α\leq 1$, from a subset of $X$ into $c_0$ can be isometrically extended to $X$ if and only if $X$ is finite dimensional. For a finite dimensional normed space $X$ and for a compact metric space $K$, we prove that the set of $α$'s for which all $α$-Hölder maps from a subset of $X$ into $C(K)$ can be extended isometrically is either $(0,1]$ or $(0,1)$ and we give examples of both occurrences. We also prove that for any metric space $X$, the described above set of $\al$'s does not depend on $K$, but only on finiteness of $K$.

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Gilles Lancien, Beata Randrianantoanina. 2004-05-28. On the extension of Hölder maps with values in spaces of continuous functions. https://arxiv.org/abs/math/0405565

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