Crouzeix's conjecture for classes of matrices
Functional Analysis
2024-01-01 v2 Numerical Analysis
Numerical Analysis
Abstract
For a matrix which satisfies Crouzeix's conjecture, we construct several classes of matrices from for which the conjecture will also hold. We discover a new link between cyclicity and Crouzeix's conjecture, which shows that Crouzeix's Conjecture holds in full generality if and only if it holds for the differentiation operator on a class of analytic functions. We pose several open questions, which if proved, will prove Crouzeix's conjecture. We also begin an investigation into Crouzeix's conjecture for symmetric matrices and in the case of matrices, we show Crouzeix's conjecture holds for symmetric matrices if and only if it holds for analytic truncated Toeplitz operators.
Keywords
Cite
@article{arxiv.2306.12183,
title = {Crouzeix's conjecture for classes of matrices},
author = {Ryan O'Loughlin and Jani Virtanen},
journal= {arXiv preprint arXiv:2306.12183},
year = {2024}
}