English

$Sz(\cdot)\leqslant \omega^\xi$ is rarely a three space property

Functional Analysis 2020-01-01 v1

Abstract

We prove that for any non-zero, countable ordinal ξ\xi which is not additively indecomposable, the property of having Szlenk index not exceeding ωξ\omega^\xi is not a three space property. This complements a result of Brooker and Lancien, which states that if ξ\xi is additively indecomposable, then having Szlenk index not exceeding ωξ\omega^\xi is a three space property.

Keywords

Cite

@article{arxiv.1912.13429,
  title  = {$Sz(\cdot)\leqslant \omega^\xi$ is rarely a three space property},
  author = {R. M. Causey},
  journal= {arXiv preprint arXiv:1912.13429},
  year   = {2020}
}