Numerical radius and zero pattern of matrices
Combinatorics
2015-06-26 v1 Functional Analysis
Abstract
We give tight upper bounds on the numerical range of square matrices in terms of their Frobenius (Euclidian) norm and a combinatorial parameter similar to the clique number of graphs. Our results imply a concise form of the fundamental theorem of Turan in extremal graph theory.
Cite
@article{arxiv.math/0703177,
title = {Numerical radius and zero pattern of matrices},
author = {Vladimir Nikiforov},
journal= {arXiv preprint arXiv:math/0703177},
year = {2015}
}