English

Another extension of the disc algebra

Complex Variables 2016-11-18 v2

Abstract

We identify the complex plane C with the open unit disc D={z:|z|<1} by the homeomorphism z --> z/(1+|z|). This leads to a compactification Cˉ\bar{C} of C, homeomorphic to the closed unit disc. The Euclidean metric on the closed unit disc induces a metric d on Cˉ\bar{C}. We identify all uniform limits of polynomials on Dˉ\bar{D} with respect to the metric d. The class of the above limits is an extension of the disc algebra and it is denoted by Aˉ(D)\bar{A}(D). We study properties of the elements of Aˉ(D)\bar{A}(D) and topological properties of the class Aˉ(D)\bar{A}(D) endowed with its natural topology. The class Aˉ(D)\bar{A}(D) is different and, from the geometric point of view, richer than the class A~(D)\tilde{A}(D) introduced in Nestoridis (2010), Arxiv:1009.5364, on the basis of the chordal metric.

Keywords

Cite

@article{arxiv.1012.3674,
  title  = {Another extension of the disc algebra},
  author = {V. Nestoridis and N. Papadatos},
  journal= {arXiv preprint arXiv:1012.3674},
  year   = {2016}
}

Comments

14 pages

R2 v1 2026-06-21T16:59:54.437Z