摘要

In this paper, it is proved that every isometry between the unit spheres of two real Banach spaces preserves the frames of the unit balls. As a consequence, if X and Y are n-dimensional Banach spaces and T-0 is an isometry from the unit sphere of X onto that of Y then it maps the set of all (n - 1)-extreme points of the unit ball of X onto that of Y.

  • 出版日期2014-10