U(X) as a Ring for Metric Spaces X

被引:9
|
作者
Cabello Sanchez, Javier [1 ]
机构
[1] Univ Extremadura, Dept Matemat, Badajoz, Spain
关键词
Rings of uniformly continuous functions; Bourbaki-boundedness; uniform isolation;
D O I
10.2298/FIL1707981C
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
In this short paper, we will show that the space of real valued uniformly continuous functions defined on a metric space (X, d) is a ring if and only if every subset A subset of X has one of the following properties: A is Bourbaki- bounded, i.e., every uniformly continuous function on X is bounded on A. A contains an infinite uniformly isolated subset, i. e., there exist delta > 0 and an infinite subset F subset of A such that d(a,x) >= delta for every a is an element of F; x is an element of X \ {a}.
引用
收藏
页码:1981 / 1984
页数:4
相关论文
共 50 条
  • [31] Cc(X) spaces with X locally compact
    Ferrando, J. C.
    Moll, S.
    ACTA MATHEMATICA SINICA-ENGLISH SERIES, 2007, 23 (09) : 1593 - 1600
  • [32] On the spaces Lp(x)(Ω) and Wm, p(x)(Ω)
    Fan, XL
    Zhao, D
    JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 2001, 263 (02) : 424 - 446
  • [33] A criterion of SNT(X) = {[X]} for hyperformal spaces
    Ni Jinsong
    CENTRAL EUROPEAN JOURNAL OF MATHEMATICS, 2009, 7 (02): : 224 - 229
  • [34] ON SPACES LP(X) AND WK,P(X)
    KOVACIK, O
    RAKOSNIK, J
    CZECHOSLOVAK MATHEMATICAL JOURNAL, 1991, 41 (04) : 592 - 618
  • [35] Cc (X) Spaces with X Locally Compact
    J. C. Ferrando
    S. Moll
    Acta Mathematica Sinica, English Series, 2007, 23 : 1593 - 1600
  • [36] Unusual X inactivation: an active ring(X).
    Shago, M
    Antinucci, D
    Chakraborty, R
    Sgro, M
    Barozzino, T
    Chitayat, D
    Teshima, I
    AMERICAN JOURNAL OF HUMAN GENETICS, 2001, 69 (04) : 322 - 322
  • [37] RING C(X) DETERMINES CATEGORY OF X
    COMFORT, WW
    NEGREPON.S
    PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY, 1965, 16 (05) : 1041 - &
  • [38] ON THE INCLUSIONS OF XΦ SPACES
    Tabatabaie, Seyyed Mohammad
    Salec, Alireza Bagheri
    MATHEMATICA BOHEMICA, 2023, 148 (01): : 65 - 72
  • [39] Porosity of XΦ Spaces
    Salec, AliReza Bagheri
    Khaleel, Ahmed Haroon
    IRANIAN JOURNAL OF SCIENCE, 2025, 49 (02) : 495 - 503
  • [40] -Δu+a(x)u=b(x)u(n+2)/(n-2)+g(x,u)的正解
    刘早清
    袁泽正
    田天海
    湖北工学院学报, 1997, (01) : 96 - 99