Fixed point theorems in R-trees with applications to graph theory

It is proved that a commutative family of nonexpansive mappings of a complete -tree X into itself always has a nonempty common fixed point set if X does not contain a geodesic ray. As a consequence of this, we show that any commuting family of edge preserving mappings of a connected reflexive graph...

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Detalles Bibliográficos
Autores: Espínola García, Rafael, Kirk, W. A.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/181662
Acceso en línea:https://hdl.handle.net/11441/181662
https://doi.org/10.1016/j.topol.2005.03.001
Access Level:acceso abierto
Palabra clave:Fixed points
Nonexpansive mappings
R-trees
Fixed edge theorem
Descripción
Sumario:It is proved that a commutative family of nonexpansive mappings of a complete -tree X into itself always has a nonempty common fixed point set if X does not contain a geodesic ray. As a consequence of this, we show that any commuting family of edge preserving mappings of a connected reflexive graph G that contains no cycles or infinite paths always has at least one common fixed edge. This approach provides a new proof of the classical fixed edge theorem of Nowakowski and Rival. Several related results are also obtained.