English

The quotient shapes of normed spaces and application

Functional Analysis 2019-03-18 v1

Abstract

The quotient shape types of normed vectorial spaces(over the same field) with respect to Banach spaces reduce to those of Banach spaces. The finite quotient shape type of normed spaces is an invariant of the (algebraic) dimension, but not conversely. The converse holds for separable normed spaces as well as for the bidual-like spaces (isomorphic to their second dual spaces). As a consequence, the Hilbert space l2l_2, or even its (countably dimensional, unitary) direct sum subspace may represent the unique quotient shape type of all 202^\aleph_0-dimensional normed spaces. An application yields two extension type theorems.

Keywords

Cite

@article{arxiv.1903.06456,
  title  = {The quotient shapes of normed spaces and application},
  author = {Nikica Uglesic},
  journal= {arXiv preprint arXiv:1903.06456},
  year   = {2019}
}