首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Note on separate continuity and the Namioka property
Authors:Dennis K Burke  Roman Pol
Institution:a Department of Mathematics, Miami University, Oxford, OH 45056, USA
b Warsaw University, Poland
Abstract:A pair 〈B,K〉 is a Namioka pair if K is compact and for any separately continuous View the MathML source, there is a dense AB such that f is ( jointly) continuous on A×K. We give an example of a Choquet space B and separately continuous View the MathML source such that the restriction fΔ| to the diagonal does not have a dense set of continuity points. However, for K a compact fragmentable space we have: For any separately continuous View the MathML source and for any Baire subspace F of T×K, the set of points of continuity of View the MathML source is dense in F. We say that 〈B,K〉 is a weak-Namioka pair if K is compact and for any separately continuous View the MathML source and a closed subset F projecting irreducibly onto B, the set of points of continuity of fF| is dense in F. We show that T is a Baire space if the pair 〈T,K〉 is a weak-Namioka pair for every compact K. Under (CH) there is an example of a space B such that 〈B,K〉 is a Namioka pair for every compact K but there is a countably compact C and a separately continuous View the MathML source which has no dense set of continuity points; in fact, f does not even have the Baire property.
Keywords:primary  54D30  secondary  54C05  54H05
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号