当前位置: X-MOL 学术Topol. Appl. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
On discrete reflexivity of Lindelöf degree and pseudocharacter
Topology and its Applications ( IF 0.6 ) Pub Date : 2021-07-01 , DOI: 10.1016/j.topol.2021.107764
O.T. Alas , V.V. Tkachuk , R.G. Wilson

We establish that any Hausdorff discretely κ-Lindelöf space X must be κ-Lindelöf if t(X)κ. Besides, in κ-Lindelöf spaces whose tightness does not exceed κ, the property of having pseudocharacter ≤κ must be discretely reflexive. Under the hypothesis c<ωω we prove that countable pseudocharacter is discretely reflexive in Lindelöf Σ-spaces. If X is a Tychonoff space and ψ(D)κ for any discrete set DCp(X), then κ+ is a caliber of X, we have the inequality hd(X×X)2κ and ψ(Y)κ for any Y[Cp(X)]κ+; this implies that ψ(Cp(X))2κ. We also show that the property of having pseudocharacter ≤κ is discretely reflexive in Cp(X) whenever X is a compact space with t(X)κ.



中文翻译:

林德洛夫度和伪特征的离散自反性

我们确定任何 Hausdorff 离散κ -Lindelöf 空间X必须是κ -Lindelöf 如果(X)κ. 此外,在紧密度不超过κ 的κ -Lindelöf 空间中,具有伪字符≤ κ 的性质必须是离散自反的。根据假设C<ωω我们证明了可数伪字符在 Lindelöf Σ-空间中是离散自反的。如果X是 Tychonoff 空间并且ψ(D)κ 对于任何离散集 DC(X), 然后 κ+X的口径,我们有不等式Hd(X×X)2κψ()κ 对于任何 [C(X)]κ+; 这意味着ψ(C(X))2κ. 我们还表明,具有伪字符 ≤ κ的属性在C(X)每当X是紧致空间时(X)κ.

更新日期:2021-07-09
down
wechat
bug