Products of $k$-spaces, and special countable spaces
نویسندگان
چکیده
منابع مشابه
Products of ¿-spaces and Spaces of Countable Tightness
In this paper, we obtain results of the following type: if /: X -» Y is a closed map and X is some "nice" space, and Y2 is a &-space or has countable tightness, then the boundary of the inverse image of each point of Y is "small" in some sense, e.g., Lindelöf or «¿¡-compact. We then apply these results to more special cases. Most of these applications combine the "smallness" of the boundaries o...
متن کاملCountable Products of Spaces of Finite Sets
σn(Γ) = {x ∈ {0, 1} Γ : |supp(x)| ≤ n}. Here supp(x) = {γ ∈ Γ : xγ 6= 0}. This is a closed, hence compact subset of {0, 1}, which is identified with the family of all subsets of Γ of cardinality at most n. In this work we will study the spaces which are countable products of spaces σn(Γ), mainly their topological classification as well as the classification of their Banach spaces of continuous ...
متن کاملsome properties of fuzzy hilbert spaces and norm of operators
in this thesis, at first we investigate the bounded inverse theorem on fuzzy normed linear spaces and study the set of all compact operators on these spaces. then we introduce the notions of fuzzy boundedness and investigate a new norm operators and the relationship between continuity and boundedness. and, we show that the space of all fuzzy bounded operators is complete. finally, we define...
15 صفحه اولCountable sums and products of Loeb and selective metric spaces
(a) X is said to be a Loeb space i® the family of all non-empty, closed subsets of X has a choice function. (b) X is said to be selective i® the family of all non-empty, open subsets of X has a choice function. (c) X is said to be locally compact i® each point in X has a neighborhood base consisting of compact sets. (d) X is called second countable if it has a countable base for T . (e) X is ca...
متن کاملProducts of k-spaces, and questions
As is well-known, every product of a locally compact space with a k-space is a k-space. But, the product of a separable metric space with a k-space need not be a k-space. In this paper, we consider conditions for products to be k-spaces, and pose some related questions.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Tsukuba Journal of Mathematics
سال: 2003
ISSN: 0387-4982
DOI: 10.21099/tkbjm/1496164657