Maximal countably compact spaces and embeddings in MP-spaces

被引:2
|
作者
Tkachuk, V. V. [1 ]
Wilson, R. G. [1 ]
机构
[1] Univ Autonoma Metropolitana, Dept Matemat, Mexico City 09340, DF, Mexico
关键词
pseudocompact space; maximal pseudocompact space; MP-space; compact space; countably compact space; MCC-space; embedding; functional tightness; Mazur property; maximal countably compact space;
D O I
10.1007/s10474-014-0469-2
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
We study embeddings in maximal pseudocompact spaces together with maximal countable compactness in the class of Tychonoff spaces. It is proved that under MA CH any compact space of weight is a retract of a compact maximal pseudocompact space. If kappa is strictly smaller than the first weakly inaccessible cardinal, then the Tychonoff cube [0, 1](kappa) is maximal countably compact. However, for a measurable cardinal kappa, the Tychonoff cube of weight kappa is not even embeddable in a maximal countably compact space. We also show that if X is a maximal countably compact space, then the functional tightness of X is countable. It is independent of ZFC whether every compact space of countable tightness must be maximal countably compact. On the other hand, any countably compact space X with the Mazur property ( every real-valued sequentially continuous function on X is continuous) must be maximal countably compact. We prove that for any omega-monolithic compact space X, if C (p) (X) has the Mazur property, then it is a Fr,chet-Urysohn space.
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页码:191 / 204
页数:14
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