English

Norms of Minimal Projections

Functional Analysis 2016-09-06 v1

Abstract

It is proved that the projection constants of two- and three-dimensional spaces are bounded by 4/34/3 and (1+5)/2(1+\sqrt 5)/2, respectively. These bounds are attained precisely by the spaces whose unit balls are the regular hexagon and dodecahedron. In fact, a general inequality for the projection constant of a real or complex nn-dimensional space is obtained and the question of equality therein is discussed.

Keywords

Cite

@article{arxiv.math/9211211,
  title  = {Norms of Minimal Projections},
  author = {Hermann König and Nicole Tomczak-Jaegermann},
  journal= {arXiv preprint arXiv:math/9211211},
  year   = {2016}
}