ملخص
Abstract
For a locally compact space, we define an order-anti-isomorphism from the set of all one-point extensions of onto the set of all nonempty closed subsets of . We consider various sets of one-point extensions, including the set of all one-point locally compact extensions of , the set of all one-point Lindelöf extensions of , the set of all one-point pseudocompact extensions of , and the set of all one-point Cech-complete extensions of , among others. We study how these sets of one-point extensions are related, and investigate the relationship between their order structure, and the topology of subspaces of , we also study the relationship between various subsets of one-point extensions, the existence of minimal and maximal elements in various sets of one point extensions, and we show how some of our results may be applied to obtain relations between the order structure of certain subfamilies of ideals of partially ordered with inclusion, and the topology of subspaces of .