Products of straight spaces with compact spaces

Authors

  • Kusuo Nishijima Shizuoka University
  • Kohzo Yamada Shizuoka University

DOI:

https://doi.org/10.4995/agt.2007.1877

Keywords:

Straight spaces, Convergent sequence, Precompact, Uniformly continuous

Abstract

A metric space X is called straight if any continuous real-valued function which is uniformly continuous on each set of a finite cover of X by closed sets, is itself uniformly continuous. Let C be the convergent sequence {1/n : n ϵ N} with its limit 0 in the real line with the usual metric. In this paper, we show that for a straight space X, X × C is straight if and only if X × K is straight for any compact metric space K. Furthermore, we show that for a straight space X, if X × C is straight, then X is precompact. Note that the notion of straightness depends on the metric on X. Indeed, since the real line R with the usual metric is not precompact, R×C is not straight. On the other hand, we show that the product space of an open interval and C is straight.

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Author Biographies

Kusuo Nishijima, Shizuoka University

Faculty of Education

Kohzo Yamada, Shizuoka University

Faculty of Education

References

M. Atsuji, Uniform continuity of continuous functions on metric spaces, Pacific J. Math. 8 (1958), 11–16. http://dx.doi.org/10.2140/pjm.1958.8.11

M. Atsuji, Uniform continuity of continuous functions on metric spaces, Canad. J. Math. 13 (1961), 657–663. http://dx.doi.org/10.4153/CJM-1961-055-9

A. Berarducci, D. Dikranjan and J. Pelant, An additivity theorem for uniformly continuous functions, Topology Appl. 146-147 (2005), 339–352. http://dx.doi.org/10.1016/j.topol.2003.05.007

A. Berarducci, D. Dikranjan and J. Pelant, Local connectedness and extension of uniformly continuous functions, preprint.

A. Berarducci, D. Dikranjan and J. Pelant, Products of straight spaces, preprint.

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How to Cite

[1]
K. Nishijima and K. Yamada, “Products of straight spaces with compact spaces”, Appl. Gen. Topol., vol. 8, no. 2, pp. 151–159, Oct. 2007.

Issue

Section

Regular Articles