English

Fourier coefficients of normalized Cauchy transforms

Complex Variables 2024-10-28 v1 Functional Analysis

Abstract

We consider a uniqueness problem concerning the Fourier coefficients of normalized Cauchy transforms. These problems inherently involve proving a simultaneous approximation phenomenon and establishing the existence of cyclic inner functions in certain sequence spaces. Our results have several applications in different directions. First, we offer a new non-probabilistic proof of a classic theorem by Kahane and Katzenelson on simultaneous approximation. Secondly, we demonstrate the absence of uniform admissible majorants of Fourier coefficients in de Branges-Rovnyak spaces.

Keywords

Cite

@article{arxiv.2410.19581,
  title  = {Fourier coefficients of normalized Cauchy transforms},
  author = {Adem Limani},
  journal= {arXiv preprint arXiv:2410.19581},
  year   = {2024}
}

Comments

16 pages

R2 v1 2026-06-28T19:35:36.117Z