English

Bands in partially ordered vector spaces with order unit

Functional Analysis 2014-05-16 v1

Abstract

In an Archimedean directed partially ordered vector space XX one can define the concept of a band in terms of disjointness. Bands can be studied by using a vector lattice cover YY of XX. If XX has an order unit, YY can be represented as C(Ω)C(\Omega), where Ω\Omega is a compact Hausdorff space. We characterize bands in XX, and their disjoint complements, in terms of subsets of Ω\Omega. We also analyze two methods to extend bands in XX to C(Ω)C(\Omega) and show how the carriers of a band and its extensions are related. We use the results to show that in each nn-dimensional partially ordered vector space with a closed generating cone, the number of bands is bounded by 1422n\frac{1}{4}2^{2^n} for n2n\geq 2. We also construct examples of (n+1)(n+1)-dimensional partially ordered vector spaces with (2nn)+2{2n\choose n}+2 bands. This shows that there are nn-dimensional partially ordered vector spaces that have more bands than an nn-dimensional Archimedean vector lattice when n4n\geq 4.

Keywords

Cite

@article{arxiv.1405.3844,
  title  = {Bands in partially ordered vector spaces with order unit},
  author = {Anke Kalauch and Bas Lemmens and Onno van Gaans},
  journal= {arXiv preprint arXiv:1405.3844},
  year   = {2014}
}

Comments

24 pages,1 figure

R2 v1 2026-06-22T04:14:58.656Z