English

On Aumann's Theorem that the sphere does not admit a mean

General Topology 2013-10-08 v1

Abstract

We prove that the circle S_1 does not have a 2-mean, i.e., S_1 times S_1 cannot have a retraction r onto its diagonal with r(x,y) = r(y,x), whenever x,y in S_1. Our proof is combinatorial and topological rather than analytical.

Cite

@article{arxiv.math/0501305,
  title  = {On Aumann's Theorem that the sphere does not admit a mean},
  author = {F. Javier Trigos-Arrieta and Marian Turzanski},
  journal= {arXiv preprint arXiv:math/0501305},
  year   = {2013}
}

Comments

6 pages

R2 v1 2026-07-22T17:14:40.966Z