A note on consonance of $G-δ$ subsets
Bouziad, Ahmed
HAL, hal-00373423 / Harvested from HAL
A space X is said to be consonant if, on the set of closed subsets of X, the upper Kuratowski topology coincides with the co-compact topology. It is known that Cech-complete spaces are consonant and that consonance is neither preserved by $G_δ$, subsets nor stable under products. We show that all $G_δ$ subspaces of a consonant space X are consonant if the Vietoris topology on compact subsets of X is hereditarily Baire; and that is always the case if all compact subspaces of X are separable and of countable character in X. Spaces which are $G_δ$ subspaces of consonant paracompact p-spaces are also shown to be consonant. Concerning products, we show that the product of a consonant paracompact p-space and a Cech-complete space is consonant. We also answer some questions of Nogura and Shakhmatov related to product and topological sum operations in the class of regular consonant spaces.
Publié le : 1998-07-05
Classification:  Hyperspaces,  Vietoris topology,  Kuratowski convergence,  Co-compact topology,  Baire category,  54B20; 54A10, Secondary 54B05; 54BlO; 54E52; 54C60,  [MATH.MATH-GN]Mathematics [math]/General Topology [math.GN]
@article{hal-00373423,
     author = {Bouziad, Ahmed},
     title = {A note on consonance of $G-$\delta$$ subsets},
     journal = {HAL},
     volume = {1998},
     number = {0},
     year = {1998},
     language = {en},
     url = {http://dml.mathdoc.fr/item/hal-00373423}
}
Bouziad, Ahmed. A note on consonance of $G-δ$ subsets. HAL, Tome 1998 (1998) no. 0, . http://gdmltest.u-ga.fr/item/hal-00373423/