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Hauptverfasser: Cúth, Marek, Havelka, Jonáš, Rondoš, Jakub, Sarı, Bünyamin
Format: Preprint
Veröffentlicht: 2026
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Online-Zugang:https://arxiv.org/abs/2601.11463
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author Cúth, Marek
Havelka, Jonáš
Rondoš, Jakub
Sarı, Bünyamin
author_facet Cúth, Marek
Havelka, Jonáš
Rondoš, Jakub
Sarı, Bünyamin
contents We study the classification of spaces of continuous functions $C(K)$ under positive linear maps. For infinite countable compacta, we show that whenever $C(K)$ and $C(L)$ are isomorphic, there exists an isomorphism $T:C(K)\to C(L)$ satisfying either $T\geq 0$ or $T^{-1}\geq 0$. We also prove that for any compact spaces $K$ and $L$, the existence of a positive embedding $T: C(K) \to C(L)$ implies that the Cantor-Bendixson height of $K$ does not exceed the height of $L$. Furthermore, we introduce a one-sided positive Banach-Mazur distance and obtain new estimates for both the classical and positive distances. Notably, we prove the exact formula $d_{BM}(C(ω^{ω^α}), C(ω^{ω^αn})) = n+\sqrt{(n-1)(n+3)}$.
format Preprint
id arxiv_https___arxiv_org_abs_2601_11463
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The classification of $C(K)$ spaces for countable compacta by positive isomorphisms
Cúth, Marek
Havelka, Jonáš
Rondoš, Jakub
Sarı, Bünyamin
Functional Analysis
We study the classification of spaces of continuous functions $C(K)$ under positive linear maps. For infinite countable compacta, we show that whenever $C(K)$ and $C(L)$ are isomorphic, there exists an isomorphism $T:C(K)\to C(L)$ satisfying either $T\geq 0$ or $T^{-1}\geq 0$. We also prove that for any compact spaces $K$ and $L$, the existence of a positive embedding $T: C(K) \to C(L)$ implies that the Cantor-Bendixson height of $K$ does not exceed the height of $L$. Furthermore, we introduce a one-sided positive Banach-Mazur distance and obtain new estimates for both the classical and positive distances. Notably, we prove the exact formula $d_{BM}(C(ω^{ω^α}), C(ω^{ω^αn})) = n+\sqrt{(n-1)(n+3)}$.
title The classification of $C(K)$ spaces for countable compacta by positive isomorphisms
topic Functional Analysis
url https://arxiv.org/abs/2601.11463