Uniform continuity in ωμ-metric spaces and uc ωμ-metric extendability

被引:0
作者
Di Concilio, A. [1 ]
Guadagni, C. [1 ]
机构
[1] Univ Salerno, Dept Math, Salerno, Italy
关键词
Nagata extension; uniform space; uniform space with a totally ordered base; omega(mu)-metric space; uc-ness in omega(mu)-metric space; omega(mu)-additive topological space; Hausdorff-Bourbaki uniformity; Hausdorff convergence; Vietoris topology; pseudo-Cauchy net; METRIC-SPACES;
D O I
10.1007/s10474-016-0643-9
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Generally, the term uc-ness means some continuity is uniform. A metric space X is uc when any continuous function fromX to [0, 1] is uniformly continuous and a metrizable space X is a Nagata space when it can be equipped with a uc metric. We consider natural forms of uc-ness for the -metric spaces, which fill a very large and interesting class of uniform spaces containing the usual metric ones, and extend to them various different formulations of the metric uc-ness, by additionaly proving their equivalence. Furthermore, since any -compact space is uc and any uc -metric space is complete, in the line of constructing dense extensions which preserve some structure, such as uniform completions, we focus on the existence for an -metrizable space of dense topological extensions carrying a uc -metric. In this paper we show that an -metrizable space X is uc-extendable if and only if there exists a compatible -metric d on X such that the set X' of all accumulation points in X is crowded, i.e., any -sequence in X' has a d-Cauchy -subsequence in X'.
引用
收藏
页码:153 / 166
页数:14
相关论文
共 34 条
[1]  
Alfsen E.M., 1963, FUND MATH, V52, P253
[2]  
[Anonymous], 2009, PROXIMITY APPROACH P
[3]  
Artico G., 1982, REND SEMIN MAT U PAD, V67, P131
[4]  
Artico G., 1996, B POL ACAD SCI MATH, V44, P299
[5]   UNIFORM CONTINUITY OF CONTINUOUS FUNCTIONS ON UNIFORM SPACES [J].
ATSUJI, M .
CANADIAN JOURNAL OF MATHEMATICS, 1961, 13 (04) :657-&
[6]  
Atsuji M., 1958, Pac. J. Math, V8, P11, DOI DOI 10.2140/PJM.1958.8.11
[8]   UC SPACES REVISITED [J].
BEER, G .
AMERICAN MATHEMATICAL MONTHLY, 1988, 95 (08) :737-739
[9]   MORE ABOUT METRIC-SPACES ON WHICH CONTINUOUS-FUNCTIONS ARE UNIFORMLY CONTINUOUS [J].
BEER, G .
BULLETIN OF THE AUSTRALIAN MATHEMATICAL SOCIETY, 1986, 33 (03) :397-406
[10]  
Beer G., 1993, TOPOLOGIES CLOSED CL