Some Characterizations of Developable Spaces
نویسنده
چکیده
Two characterizations of developable spaces are proved which may be viewed as analogues, for developable spaces, of the Nagata-Smirnov metrization theorem or of the "double sequence metrization theorem " of Nagata respectively.
منابع مشابه
On π-s-images of metric spaces
In 1966, Michael [11] introduced the concept of compact-covering maps. Since many important kinds of maps are compact-covering, such as closed maps on paracompact spaces, much work has been done to seek the characterizations of metric spaces under various compact-covering maps, for example, compact-covering (open) s-maps, pseudosequence-covering (quotient) s-maps, sequence-covering (quotient) s...
متن کاملSome Characterizations of Hopf Group on Fuzzy Topological Spaces
In this paper, some fundamental concepts are given relating to fuzzytopological spaces. Then it is shown that there is a contravariant functorfrom the category of the pointed fuzzy topological spaces to the category ofgroups and homomorphisms. Also the fuzzy topological spaces which are Hopfspaces are investigated and it is shown that a pointed fuzzy toplogicalspace having the same homotopy typ...
متن کاملNew characterizations of fusion bases and Riesz fusion bases in Hilbert spaces
In this paper we investigate a new notion of bases in Hilbert spaces and similar to fusion frame theory we introduce fusion bases theory in Hilbert spaces. We also introduce a new denition of fusion dual sequence associated with a fusion basis and show that the operators of a fusion dual sequence are continuous projections. Next we dene the fusion biorthogonal sequence, Bessel fusion basis, Hil...
متن کاملCharacterizations and properties of bounded $L$-fuzzy sets
In 1997, Fang proposed the concept of boundedness of $L$-fuzzy setsin $L$-topological vector spaces. Since then, this concept has beenwidely accepted and adopted in the literature. In this paper,several characterizations of bounded $L$-fuzzy sets in$L$-topological vector spaces are obtained and some properties ofbounded $L$-fuzzy sets are investigated.
متن کاملA remark on Remainders of homogeneous spaces in some compactifications
We prove that a remainder $Y$ of a non-locally compact rectifiable space $X$ is locally a $p$-space if and only if either $X$ is a Lindel"{o}f $p$-space or $X$ is $sigma$-compact, which improves two results by Arhangel'skii. We also show that if a non-locally compact rectifiable space $X$ that is locally paracompact has a remainder $Y$ which has locally a $G_{delta}$-diagonal, then...
متن کامل