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Factorizations of normality via generalizations of $\beta$-normality

Ananga Kumar Das, Pratibha Bhat, Ria Gupta

Received August 16, 2015.   First published September 12, 2016.

Abstract: The notion of $\beta$-normality was introduced and studied by Arhangel'skii, Ludwig in 2001. Recently, almost $\beta$-normal spaces, which is a simultaneous generalization of $\beta$-normal and almost normal spaces, were introduced by Das, Bhat and Tartir. We introduce a new generalization of normality, namely weak $\beta$-normality, in terms of $\theta$-closed sets, which turns out to be a simultaneous generalization of $\beta$-normality and $\theta$-normality. A space $X$ is said to be weakly $\beta$-normal (w$\beta$-normal$)$ if for every pair of disjoint closed sets $A$ and $B$ out of which, one is $\theta$-closed, there exist open sets $U$ and $V$ such that $\overline{A\cap U}=A$, $\overline{B\cap V}=B$ and $\overline{U}\cap\overline{V}=\emptyset$. It is shown that w$\beta$-normality acts as a tool to provide factorizations of normality.

Keywords: normal space; (weakly) densely normal space; (weakly) $\theta$-normal space; almost normal space; almost $\beta$-normal space; $\kappa$-normal space; (weakly) $\beta$-normal space

Classification (MSC 2010): 54D15

DOI: 10.21136/MB.2016.0048-15

Full text available as PDF.

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