English

A generalized eigenvector-eigenvalue identity from the viewpoint of exterior algebra

Rings and Algebras 2025-04-01 v2

Abstract

We consider square matrices over C\mathbb{C} satisfying an identity relating their eigenvalues and the corresponding eigenvectors re-proved and discussed by Denton, Parker, Tao and Zhang, called the eigenvector-eigenvalue identity. We prove that for an eigenvalue λ\lambda of a given matrix the identity holds if and only if the geometric multiplicity of λ\lambda equals its algebraic multiplicity. We do not make any other assumptions on the matrix and allow the multiplicity of the eigenvalue to be greater than 1, which provides a substantial generalization of the identity. In the proof we use exterior algebra, particularly the properties of higher adjugates of a matrix.

Keywords

Cite

@article{arxiv.1912.06967,
  title  = {A generalized eigenvector-eigenvalue identity from the viewpoint of exterior algebra},
  author = {Malgorzata Stawiska},
  journal= {arXiv preprint arXiv:1912.06967},
  year   = {2025}
}
R2 v1 2026-06-23T12:46:12.045Z