Continuous selections avoiding extreme points

被引:3
作者
Yamauchi, Takamitsu [1 ]
机构
[1] Shimane Univ, Dept Math, Matsue, Shimane 6908504, Japan
关键词
set-valued mapping; selection; extreme point; countable paracompactness;
D O I
10.1016/j.topol.2007.02.016
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
It is shown that if X is a countably paracompact collectionwise normal space, Y is a Banach space and phi : X -> 2(Y) is a lower semicontinuous mapping such that phi(x) is Y or a compact convex subset with Card phi(x) > 1 for each X epsilon X, then phi admits a continuous selection f : X -> Y such that f (x) is not an extreme point of phi(x) for each X E X. This is an affirmative answer to the problem posed by V. Gutev, H. Ohta and K. Yamazaki [V. Gutev, H. Ohta and K. Yamazaki, Selections and sandwich-like properties via semi-continuous Banach-valued functions, J. Math. Soc. Japan 55 (2003) 499-521]. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:916 / 922
页数:7
相关论文
共 12 条
[1]  
[Anonymous], GRADUATE TEXTS MATH
[2]  
Coban C M. M., 1975, C R ACAD BULGARE SCI, V28, P871
[3]  
DOWKER C. H., 1952, Ark. Mat., V2, P307, DOI 10.1007/BF02591500
[4]   ON COUNTABLY PARACOMPACT SPACES [J].
DOWKER, CH .
CANADIAN JOURNAL OF MATHEMATICS-JOURNAL CANADIEN DE MATHEMATIQUES, 1951, 3 (02) :219-224
[5]  
Engelking R., 1989, General Topology, V2
[6]   Selections and sandwich-like properties via semi-continuous Banach-valued functions [J].
Gutev, V ;
Ohta, H ;
Yamazaki, K .
JOURNAL OF THE MATHEMATICAL SOCIETY OF JAPAN, 2003, 55 (02) :499-521
[7]  
KATETOV M, 1998, FUND MATH, V183
[8]   CONTINUOUS SELECTIONS .1. [J].
MICHAEL, E .
ANNALS OF MATHEMATICS, 1956, 63 (02) :361-382
[9]  
Michael E., 1955, Can. J. Math., V7, P275
[10]  
NEDEV S., 1980, Serdica Math. J., V6, P291