Topological Methods in Nonlinear Analysis

Lipschitz retractions onto sphere vs spherical cup in a Hilbert space

Jumpot Intrakul, Phichet Chaoha, and Wacharin Wichiramala

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We prove that, in every infinite dimensional Hilbert space, there exists $t_0>-1$ such that the smallest Lipscthiz constant of retractions from the unit ball onto its boundary is the same as the smallest Lipschitz constant of retractions from the unit ball onto its $t$-spherical cup for all $t\in[-1,t_0]$.

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Topol. Methods Nonlinear Anal., Volume 52, Number 2 (2018), 677-691.

First available in Project Euclid: 25 November 2018

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Intrakul, Jumpot; Chaoha, Phichet; Wichiramala, Wacharin. Lipschitz retractions onto sphere vs spherical cup in a Hilbert space. Topol. Methods Nonlinear Anal. 52 (2018), no. 2, 677--691. doi:10.12775/TMNA.2018.034.

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