On minimal strongly KC-spaces
Czechoslovak Mathematical Journal, Tome 59 (2009) no. 2, pp. 305-316
Cet article a éte moissonné depuis la source Czech Digital Mathematics Library
In this article we introduce the notion of strongly ${\rm KC}$-spaces, that is, those spaces in which countably compact subsets are closed. We find they have good properties. We prove that a space $(X, \tau )$ is maximal countably compact if and only if it is minimal strongly ${\rm KC}$, and apply this result to study some properties of minimal strongly ${\rm KC}$-spaces, some of which are not possessed by minimal ${\rm KC}$-spaces. We also give a positive answer to a question proposed by O. T. Alas and R. G. Wilson, who asked whether every countably compact ${\rm KC}$-space of cardinality less than $c$ has the ${\rm FDS }$-property. Using this we obtain a characterization of Katětov strongly ${\rm KC}$-spaces and finally, we generalize one result of Alas and Wilson on Katětov-${\rm KC}$ spaces.
In this article we introduce the notion of strongly ${\rm KC}$-spaces, that is, those spaces in which countably compact subsets are closed. We find they have good properties. We prove that a space $(X, \tau )$ is maximal countably compact if and only if it is minimal strongly ${\rm KC}$, and apply this result to study some properties of minimal strongly ${\rm KC}$-spaces, some of which are not possessed by minimal ${\rm KC}$-spaces. We also give a positive answer to a question proposed by O. T. Alas and R. G. Wilson, who asked whether every countably compact ${\rm KC}$-space of cardinality less than $c$ has the ${\rm FDS }$-property. Using this we obtain a characterization of Katětov strongly ${\rm KC}$-spaces and finally, we generalize one result of Alas and Wilson on Katětov-${\rm KC}$ spaces.
Classification :
54A10, 54D25, 54D55
Keywords: ${\rm KC}$-space; strongly ${\rm KC}$-space; ${\rm FDS}$-property; maximal (countably) compact
Keywords: ${\rm KC}$-space; strongly ${\rm KC}$-space; ${\rm FDS}$-property; maximal (countably) compact
@article{CMJ_2009_59_2_a2,
author = {Sun, Weihua and Xu, Yuming and Li, Ning},
title = {On minimal strongly {KC-spaces}},
journal = {Czechoslovak Mathematical Journal},
pages = {305--316},
year = {2009},
volume = {59},
number = {2},
mrnumber = {2532377},
zbl = {1224.54011},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMJ_2009_59_2_a2/}
}
Sun, Weihua; Xu, Yuming; Li, Ning. On minimal strongly KC-spaces. Czechoslovak Mathematical Journal, Tome 59 (2009) no. 2, pp. 305-316. http://geodesic.mathdoc.fr/item/CMJ_2009_59_2_a2/