Topological properties of function spaces over ordinals

被引:0
作者
Saak Gabriyelyan
Jan Grebík
Jerzy Ka̧kol
Lyubomyr Zdomskyy
机构
[1] Ben-Gurion University of the Negev,Department of Mathematics
[2] Czech Academy of Sciences,Institute of Mathematics
[3] A. Mickiewicz University,Institute of Mathematics
[4] Czech Academy of Sciences,Kurt Gödel Research Center for Mathematical Logic
[5] University of Vienna,undefined
来源
Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A. Matemáticas | 2017年 / 111卷
关键词
Ascoli; -space; Ordinal space; 54C35; 54F05; 46A08; 54E18;
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学科分类号
摘要
A topological space X is said to be an Ascoli space if any compact subset K\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathcal {K}$$\end{document} of Ck(Y)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_k(Y)$$\end{document} is evenly continuous. This definition is motivated by the classical Ascoli theorem. We study the kR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_\mathbb {R}$$\end{document}-property and the Ascoli property of Cp(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_{p}(\kappa )$$\end{document} and Ck(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_k(\kappa )$$\end{document} over ordinals κ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\kappa $$\end{document}. We prove that Cp(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_p(\kappa )$$\end{document} is always an Ascoli space, while Cp(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_p(\kappa )$$\end{document} is a kR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_\mathbb {R}$$\end{document}-space iff the cofinality of κ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\kappa $$\end{document} is countable. In particular, this provides the first Cp\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_{p}$$\end{document}-example of an Ascoli space which is not a kR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_\mathbb {R}$$\end{document}-space, namely Cp(ω1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_p(\omega _1)$$\end{document}. We show that Ck(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_k(\kappa )$$\end{document} is Ascoli iff cf(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm {cf}(\kappa )$$\end{document} is countable iff Ck(κ)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_k(\kappa )$$\end{document} is metrizable.
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页码:1157 / 1161
页数:4
相关论文
共 11 条
[1]  
Arhangel’skii AV(2001)Normality and dense subspaces Proc. Am. Math. Soc. 48 283-291
[2]  
Banakh T(2016)On the Monatshefte Math. 180 39-64
[3]  
Gabriyelyan S(2016)-stable closure of the class of (separable) metrizable spaces Stud. Math. 233 119-139
[4]  
Gabriyelyan S(1990)The Ascoli property for function spaces and the weak topology on Banach and Fréchet spaces Math. Notes 47 329-334
[5]  
Ka̧kol J(1967)Spaces of continuous functions on ordinals and ultrafilters Pac. J. Math. 22 323-337
[6]  
Plebanek G(2006)Functional representation of topological algebras Topol. Appl. 153 2795-2804
[7]  
Gul’ko SP(1981)Two properties of Int. J. Math. 4 39-53
[8]  
Morris PD(undefined) weaker than Fréchet-Urysohn property undefined undefined undefined-undefined
[9]  
Wulbert DE(undefined)Mazur spaces undefined undefined undefined-undefined
[10]  
Sakai M(undefined)undefined undefined undefined undefined-undefined