English

Bounding Zolotarev numbers using Faber rational functions

Complex Variables 2020-05-11 v2 Numerical Analysis Numerical Analysis

Abstract

By closely following a construction by Ganelius, we construct Faber rational functions that allow us to derive tight and explicit bounds on Zolotarev numbers. We use our results to bound the singular values of matrices, including complex-valued Cauchy matrices and Vandermonde matrices with nodes inside the unit disk. We construct Faber rational functions using doubly-connected conformal maps and use their zeros and poles to supply shift parameters in the alternating direction implicit method.

Keywords

Cite

@article{arxiv.1911.11882,
  title  = {Bounding Zolotarev numbers using Faber rational functions},
  author = {Daniel Rubin and Alex Townsend and Heather Wilber},
  journal= {arXiv preprint arXiv:1911.11882},
  year   = {2020}
}

Comments

20 pages, 9 figures

R2 v1 2026-06-23T12:28:25.255Z