Geodesic
Remarks on retracting balls on spherical caps in \(c_{0}\), \(c\), \(l^{\infty }\) spaces
Annales Universitatis Mariae Curie-Skłodowska. Mathematica , Tome 74 (2020) no. 1, pp. 45-55.

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For any infinite dimensional Banach space there exists a lipschitzian retraction of the closed unit ball B onto the unit sphere S. Lipschitz constants for such retractions are, in general, only roughly estimated. The paper is illustrative. It contains remarks, illustrations and estimates concerning optimal retractions onto spherical caps for sequence spaces with the uniform norm.
Keywords: Retraction, Lipschitz constant, radial projection, truncation, spherical cap 
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Goebel, Kazimierz. Remarks on retracting balls on spherical caps in \(c_{0}\), \(c\), \(l^{\infty }\) spaces. Annales Universitatis Mariae Curie-Skłodowska. Mathematica , Tome 74 (2020) no. 1, pp. 45-55. http://geodesic.mathdoc.fr/item/AUM_2020_74_1_a0/

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