Alpha-paracompact subsets and well-situated subsets

In this paper -paracompact and well-situated subsets are further examined. A subset E of a space X is paracompact if every covering of E by open sets has a refinement by open sets, locally finite in X, which covers E [C. E. Aull, Proc. 2nd Prague Topol. Symp. 1966, 45-51 (1967; Zbl 0162.264)] and is...

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Detalhes bibliográficos
Autor: Gallego Lupiáñez, Francisco
Formato: artículo
Fecha de publicación:1988
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/57272
Acesso em linha:https://hdl.handle.net/20.500.14352/57272
Access Level:acceso abierto
Palavra-chave:515.1
-paracompact subsets
Well-situated subsets
Topología
1210 Topología
Descrição
Resumo:In this paper -paracompact and well-situated subsets are further examined. A subset E of a space X is paracompact if every covering of E by open sets has a refinement by open sets, locally finite in X, which covers E [C. E. Aull, Proc. 2nd Prague Topol. Symp. 1966, 45-51 (1967; Zbl 0162.264)] and is well-situated in X if for every paracompact T2 space Y, E × Y is -paracompact in X × Y [H. W. Martin, Topology Appl.12, 305-313 (1981; Zbl 0483.54011)]. Covering properties of -paracompact and wellsituated ubsets are obtained, -paracompact and well-situated subsets are characterizedin regular spaces, the behavior of paracompact and well-situated subsets under perfect mappings is studied, and it is shown that the class of all paracompact T2 spaceswhich are well-situated in every paracompact T2 space in which they are embedded as closed subsets, is perfect.