English

A new generalized field of values

Numerical Analysis 2010-12-20 v1

Abstract

Given a right eigenvector xx and a left eigenvector yy associated with the same eigenvalue of a matrix AA, there is a Hermitian positive definite matrix HH for which y=Hxy=Hx. The matrix HH defines an inner product and consequently also a field of values. The new generalized field of values is always the convex hull of the eigenvalues of AA. Moreover, it is equal to the standard field of values when AA is normal and is a particular case of the field of values associated with non-standard inner products proposed by Givens. As a consequence, in the same way as with Hermitian matrices, the eigenvalues of non-Hermitian matrices with real spectrum can be characterized in terms of extrema of a corresponding generalized Rayleigh Quotient.

Keywords

Cite

@article{arxiv.1012.3835,
  title  = {A new generalized field of values},
  author = {Ricardo Reis da Silva},
  journal= {arXiv preprint arXiv:1012.3835},
  year   = {2010}
}
R2 v1 2026-06-21T17:00:21.056Z