English

A note on the approximation by a sum of two algebras

Functional Analysis 2024-06-18 v2

Abstract

We consider the problem of approximation of a continuous function ff defined on a compact metric space XX by elements from a sum of two algebras. We prove a de la Vall\'{e}e Poussin type theorem, which estimates the approximation error E(f)E(f) from below. We also obtain a duality formula for the precise computation of E(f)E(f).

Keywords

Cite

@article{arxiv.2405.09815,
  title  = {A note on the approximation by a sum of two algebras},
  author = {Aida Asgarova and Vugar Ismailov},
  journal= {arXiv preprint arXiv:2405.09815},
  year   = {2024}
}

Comments

10 pages, typos corrected, references added; this paper includes material from arXiv:2204.07448