English

On Abstract Spectral Constants

Functional Analysis 2023-02-13 v1 Numerical Analysis Numerical Analysis Operator Algebras Spectral Theory

Abstract

We prove bounds for a class of unital homomorphisms arising in the study of spectral sets, by involving extremal functions and vectors. These are used to recover three celebrated results on spectral constants by Crouzeix--Palencia, Okubo--Ando and von Neumann in a unified way and to refine a recent result by Crouzeix--Greenbaum.

Keywords

Cite

@article{arxiv.2302.05389,
  title  = {On Abstract Spectral Constants},
  author = {Felix L. Schwenninger and Jens de Vries},
  journal= {arXiv preprint arXiv:2302.05389},
  year   = {2023}
}

Comments

14 pages

R2 v1 2026-06-28T08:37:16.142Z