On weak shape equivalences

We prove that weak shape equivalences are monomorphisms in the shape category of uniformly pointed movable continua Sh(M). We use an example of Draper and Keesling to show that weak shape equivalences need not be monomorphisms in the shape category. We deduce that Sh(M) is not balanced. We give a ch...

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Detalles Bibliográficos
Autores: Alonso Morón, Manuel, Romero Ruiz Del Portal, Francisco
Tipo de recurso: artículo
Fecha de publicación:1999
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/57320
Acceso en línea:https://hdl.handle.net/20.500.14352/57320
Access Level:acceso abierto
Palabra clave:515.143
Homotopy
Monomorphisms
Epimorphisms
Weak shape equivalence
Shape category of uniformly pointed movable continua
Monomorphisms and epimorphisms in categories
Topología
1210 Topología
Descripción
Sumario:We prove that weak shape equivalences are monomorphisms in the shape category of uniformly pointed movable continua Sh(M). We use an example of Draper and Keesling to show that weak shape equivalences need not be monomorphisms in the shape category. We deduce that Sh(M) is not balanced. We give a characterization of weak dominations in the shape category of pointed continua, in the sense of Dydak (1979). We introduce the class of pointed movable triples (X,F,Y), for a shape morphism F:X --> Y, and we establish an infinite-dimensional Whitehead theorem in shape theory from which we obtain, as a corollary, that for every pointed movable pair of continua (Y,X) the embedding j: X --> Y is a shape equivalence iff it is a weak shape equivalence.