Title:
|
Monotonically normal $e$-separable spaces may not be perfect (English) |
Author:
|
Porter, John E. |
Language:
|
English |
Journal:
|
Commentationes Mathematicae Universitatis Carolinae |
ISSN:
|
0010-2628 (print) |
ISSN:
|
1213-7243 (online) |
Volume:
|
59 |
Issue:
|
3 |
Year:
|
2018 |
Pages:
|
391-398 |
Summary lang:
|
English |
. |
Category:
|
math |
. |
Summary:
|
A topological space $X$ is said to be $e$-separable if $X$ has a $\sigma$-closed-discrete dense subset. Recently, G. Gruenhage and D. Lutzer showed that $e$-separable PIGO spaces are perfect and asked if $e$-separable monotonically normal spaces are perfect in general. The main purpose of this article is to provide examples of $e$-separable monotonically normal spaces which are not perfect. Extremely normal $e$-separable spaces are shown to be stratifiable. (English) |
Keyword:
|
monotonically normal space |
Keyword:
|
$\sigma$-closed-discrete dense set |
Keyword:
|
$e$-separable space |
Keyword:
|
perfect space |
Keyword:
|
perfectly normal space |
Keyword:
|
point network |
Keyword:
|
perfect images of generalized ordered space |
MSC:
|
54B10 |
MSC:
|
54D15 |
MSC:
|
54G20 |
idZBL:
|
Zbl 06940879 |
idMR:
|
MR3861561 |
DOI:
|
10.14712/1213-7243.2015.253 |
. |
Date available:
|
2018-09-10T12:19:01Z |
Last updated:
|
2020-10-05 |
Stable URL:
|
http://hdl.handle.net/10338.dmlcz/147406 |
. |
Reference:
|
[1] Balogh Z.: Topological spaces with point networks.Proc. Amer. Math. Soc. 94 (1985), no. 3, 497–501. MR 0787901, 10.1090/S0002-9939-1985-0787901-1 |
Reference:
|
[2] Borges C. R.: A study of monotonically normal spaces.Proc. Amer. Math. Soc. 38 (1973), 211–214. MR 0324644, 10.1090/S0002-9939-1973-0324644-4 |
Reference:
|
[3] Cairns P., Junilla H., Nyikos P.: An application of Mary Ellen Rudin's solution to Nikiel's conjecture.Topology Appl. 195 (2015), 26–33. MR 3414872 |
Reference:
|
[4] Collins P. J., Reed G. M., Roscoe A. W., Rudin M. E.: A lattice of conditions on topological spaces.Proc. Amer. Math. Soc. 94 (1985), 487–496. MR 0787900, 10.1090/S0002-9939-1985-0787900-X |
Reference:
|
[5] Collins P. J., Roscoe A. W.: Criteria for metrisability.Proc. Amer. Math. Soc. 90 (1984), no. 4, 631–640. Zbl 0541.54034, MR 0733418, 10.1090/S0002-9939-1984-0733418-9 |
Reference:
|
[6] Dias R. R., Soukup D. T.: On spaces with a $\sigma$-closed discrete dense sets.Topology Proc. 52 (2018), 245–264. MR 3773584 |
Reference:
|
[7] Gruenhage G., Lutzer D.: Perfect images of generalized ordered spaces.Fund. Math. 240 (2018), no. 2, 175–197. MR 3720923, 10.4064/fm343-1-2017 |
Reference:
|
[8] Gruenhage G., Zenor P.: Proto-metrizable spaces.Houston J. Math. 3 (1977), no. 1, 47–53. MR 0442895 |
Reference:
|
[9] Heath R. W., Lutzer D. J., Zenor P. L.: Monotonically normal spaces.Trans. Amer. Math. Soc. 178 (1973), 481–493. MR 0372826, 10.1090/S0002-9947-1973-0372826-2 |
Reference:
|
[10] Lutzer D. J.: On generalized ordered spaces.Dissertationes Math. Rozprawy Math. 89 (1971), 32 pages. MR 0324668 |
Reference:
|
[11] Moody P. J., Reed G. M., Roscoe A. W., Collins P. J.: A lattice of conditions on topological spaces II.Fund. Math. 138 (1991), no. 2, 69–81. MR 1124537, 10.4064/fm-138-2-69-81 |
Reference:
|
[12] Ostaszewski A. J.: Monotone normality and $G_\delta$-diagonals in the class of inductively generated spaces.Topology, Vol. II (Proc. Fourth Colloq., Budapest, 1978), 905–930; Colloq. Math. Soc. János Bolyai, 23, North-Holland, Amsterdam-New York, 1980. MR 0588837 |
Reference:
|
[13] Williams S. W., Zhou H. X.: Strong versions of normality.General Topology and Applications, Lecture Notes on Pure and Appl. Math., Dekker 134 (1991), 379–389. Zbl 0797.54011, MR 1142815 |
. |