English

A polynomial approximation result for free Herglotz-Agler functions

Functional Analysis 2023-02-14 v2 Complex Variables Operator Algebras

Abstract

In this paper, we prove a noncommutative (nc for short) analog of Schwarz lemma for the nc Schur-Agler class and prove that the regular nc Schur-Agler class and the regular free Herglotz class are homeomorphic. Moreover, we give a characterization of regular free Herglotz functions. As an application, we will show that any regular free Herglotz functions can uniformly be approximated by regular Herglotz free polynomials.

Cite

@article{arxiv.2203.14243,
  title  = {A polynomial approximation result for free Herglotz-Agler functions},
  author = {Kenta Kojin},
  journal= {arXiv preprint arXiv:2203.14243},
  year   = {2023}
}

Comments

13 pages.To appear in Canad. Math. Bull

R2 v1 2026-06-24T10:27:16.600Z