Expandability and s-expandability

Abstract

We show that every T 1 wN-space is expandable and as a corollary, we prove that a θ-renable sym-wg T 1 space is paracompact and thus two problems of Chris Good are solved. We also investigate s-expandability, and for extremally disconnected spaces, a characterization of s-expandability is given in terms of covers, which gives an extension to a known result.

Semi- I -Expandable Ideal Topological Spaces

“…Al-Zoubi [3] introduced the concept of s-expandable spaces as a variation of expandable spaces and showed that an extremally disconnected semiregular space is s-expandable if and only if it is expandable. Jiang and Sun [4] proved that every T 1 wN-space is expandable and discussed a characterization of s-expandability for extremally disconnected spaces. Al-Zoubi [5] introduced the class of S-paracompact spaces as a generalization of paracompact spaces and investigated the relationships between S-paracompact spaces and other well-known spaces.…”