Topological Methods in Nonlinear Analysis
- Topol. Methods Nonlinear Anal.
- Volume 40, Number 1 (2012), 215-224.
Around Ulam's question on retractions
It is known that the unit ball in infinitely dimensional Hilbert space can be retracted onto its boundary via a lipschitzian mapping. The magnitude of Lipschitz constant is only roughly estimated. The note contains a number of observations connected to this result and opens some new problems.
Topol. Methods Nonlinear Anal., Volume 40, Number 1 (2012), 215-224.
First available in Project Euclid: 21 April 2016
Permanent link to this document
Mathematical Reviews number (MathSciNet)
Zentralblatt MATH identifier
Chaoha, Phichet; Goebel, Kazimierz; Termwuttipong, Imchit. Around Ulam's question on retractions. Topol. Methods Nonlinear Anal. 40 (2012), no. 1, 215--224. https://projecteuclid.org/euclid.tmna/1461243460