LOCAL CONNECTEDNESS AND RETRACTIONS IN HYPERSPACES

被引:0
|
作者
Charatonik, Janusz J. [1 ]
Pellicer-Covarrubias, Patricia [1 ]
机构
[1] Univ Nacl Autonoma Mexico, Inst Matemat, Mexico City 04510, DF, Mexico
关键词
Connected im kleinen; continuum; contractible; deformation retraction; hyperspace; local basis; locally connected; retraction; strong deformation retraction;
D O I
10.1216/RMJ-2008-38-6-1927
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Given a metric continuum X, let 2(X) denote the hyperspace of all nonempty closed subsets of X; further, let C(X) (and C-2(X)) be the hyperspace of all members of 2(X) which are connected (composed of at most two components, respectively). For a point p is an element of X we consider mappings phi(p) : C(X) -> C-2(X) and psi(p) : 2(X) -> 2(X) both defined by A bar right arrow A boolean OR {p}. Relations between local connectedness of X at p and conditions under which these mappings are deformation retractions or strong deformation retractions (under a special convention for phi(p)) are studied. The conditions are related to contractibility of the corresponding hyperspaces and to the existence of a special local base of the point p.
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页码:1927 / 1935
页数:9
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