Diversities, hyperconvexity and fixed points

被引:9
作者
Espinola, Rafa [1 ]
Piatek, Bozena [2 ]
机构
[1] Univ Seville, Dpto Anal Matemat, E-41080 Seville, Spain
[2] Silesian Tech Univ, Inst Math, PL-44100 Gliwice, Poland
关键词
Diversities; Diversity tight spans; Fixed points; Hyperconvex metric space; Metric tight spans; Nonexpansive mappings; Phylogenetic; SPACES; SELECTION; MAPPINGS; TREES;
D O I
10.1016/j.na.2013.09.005
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
Diversities have been recently introduced as a generalization of metrics for which a rich tight span theory could be stated. In this work we take up a number of questions about hyperconvexity, diversities and fixed points of nonexpansive mappings. Most of these questions are motivated by the study of the connection between a hyperconvex diversity and its induced metric space for which we provide some answers. Examples are given, for instance, showing that such a metric space need not be hyperconvex but still we prove, as our main result, that they enjoy the fixed point property for nonexpansive mappings provided the diversity is bounded and that this boundedness condition cannot be transferred from the diversity to the induced metric space. (C) 2013 Elsevier Ltd. All rights reserved.
引用
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页码:229 / 245
页数:17
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