On 2-local nonlinear surjective isometries on normed spaces and C-algebras
arXiv:1907.02172
Abstract
We prove that, if the closed unit ball of a normed space has sufficiently many extreme points, then every mapping from into itself with the following property is affine: For any pair of points in , there exists a (not necessarily linear) surjective isometry on that coincides with at the two points. We also consider surjectivity of such a mapping in some special cases including C-algebras.
8 pages