Approximation and fixed points for compositions of Rδ-maps
Górniewicz, Lech ; Lassonde, Marc
HAL, hal-00699222 / Harvested from HAL
A set-valued upper semi-continuous map is called an Rδ -map if each of its values is an Rδ -set (we recall that an Rδ -set is a space that can be represented as the intersection of a decreasing sequence of compact AR-spaces). We prove that a compact set-valued map of an AR-space into itself has a fixed point provided it can be factorized by an arbitrary finite number of Rδ -maps through ANR-spaces. This fact is a consequence of a more general result which is the main goal of this note. The proof relies on a refinement of the approximation technique and does not make use of homological tools.
Publié le : 1994-07-05
Classification:  [MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA],  [MATH.MATH-GN]Mathematics [math]/General Topology [math.GN]
@article{hal-00699222,
     author = {G\'orniewicz, Lech and Lassonde, Marc},
     title = {Approximation and fixed points for compositions of R$\delta$-maps},
     journal = {HAL},
     volume = {1994},
     number = {0},
     year = {1994},
     language = {en},
     url = {http://dml.mathdoc.fr/item/hal-00699222}
}
Górniewicz, Lech; Lassonde, Marc. Approximation and fixed points for compositions of Rδ-maps. HAL, Tome 1994 (1994) no. 0, . http://gdmltest.u-ga.fr/item/hal-00699222/