Non-expansive bijections between unit balls of Banach spaces (A technical version with some boring proofs included)
arXiv:1704.06961 · doi:10.1215/20088752-2017-0050
Abstract
It is known that if is a finite-dimensional Banach space, or a strictly convex space, or the space , then every non-expansive bijection is an isometry. We extend these results to non-expansive bijections between unit balls of two different Banach spaces. Namely, if is an arbitrary Banach space and is finite-dimensional or strictly convex, or the space then every non-expansive bijection is an isometry.