On projection constant problems and the existence of metric projections in normed spaces
El-Shobaky, Entisarat ; Ali, Sahar Mohammed ; Takahashi, Wataru
Abstr. Appl. Anal., Tome 6 (2001) no. 1, p. 401-411 / Harvested from Project Euclid
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We give the sufficient conditions for the existence of a metric projection onto convex closed subsets of normed linear spaces which are reduced conditions than that in the case of reflexive Banach spaces and we find a general formula for the projections onto the maximal proper subspaces of the classical Banach spaces $l_p,1\leq p < \infty$ and $c_0$ . We also give the sufficient and necessary conditions for an infinite matrix to represent a projection operator from $l_p,1\leq p < \infty$ or $c_0$ onto anyone of their maximal proper subspaces.
Publié le : 2001-05-14
Classification:  41A50,  41A52,  46A32,  46N10 
@article{1050266950,
     author = {El-Shobaky, Entisarat and Ali, Sahar Mohammed and Takahashi, Wataru},
     title = {On projection constant problems and the existence of metric
 projections in normed spaces},
     journal = {Abstr. Appl. Anal.},
     volume = {6},
     number = {1},
     year = {2001},
     pages = { 401-411},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1050266950}
}

El-Shobaky, Entisarat; Ali, Sahar Mohammed; Takahashi, Wataru. On projection constant problems and the existence of metric
 projections in normed spaces. Abstr. Appl. Anal., Tome 6 (2001) no. 1, pp.  401-411. http://gdmltest.u-ga.fr/item/1050266950/