English

A new norm on BLO and matters of approximability and duality

Functional Analysis 2023-07-03 v1

Abstract

In this paper, we obtain an alternative expression for the distance of a function in BLOBLO from the subspace LL^\infty. The distance is the one induced by choosing a new "norm" on BLOBLO, equivalent to the usual one and that has the advantage to make the distance to LL^{\infty} explicitely and exactly computable. We also prove that this new norm has got the norm attaining property on BLOBLO. \\ We address the issue of approximability by truncation as it is not obvious even in the closure of LL^\infty in BLOBLO that functions can be approximated by truncation. As a matter of fact, a few examples of this are presented. The easier issue of approximability by convolution is also addressed.\\ In the last section we finally prove that the "dual" of VLOVLO is isometric to VMOVMO^{\ast}.

Keywords

Cite

@article{arxiv.2306.17746,
  title  = {A new norm on BLO and matters of approximability and duality},
  author = {Francesca Angrisani},
  journal= {arXiv preprint arXiv:2306.17746},
  year   = {2023}
}