The eigenvector variety of a matrix pencil
Abstract
Let be a field and natural numbers. A matrix pencil is given by matrices of the same size with coefficients in , say by -matrices, or, equivalently, by linear transformations with . We say that is reduced provided the intersection of the kernels of the linear transformations is zero. If is a reduced matrix pencil, a vector will be called an eigenvector of provided the subspace of generated by the elements is -dimensional. Eigenvectors are called equivalent provided they are scalar multiples of each other. The set of equivalence classes of eigenvectors of is a Zariski closed subset of the projective space , thus a projective variety. We call it the eigenvector variety of . The aim of this note is to show that any projective variety arises as an eigenvector variety of some reduced matrix pencil.
Keywords
Cite
@article{arxiv.1703.04097,
title = {The eigenvector variety of a matrix pencil},
author = {Claus Michael Ringel},
journal= {arXiv preprint arXiv:1703.04097},
year = {2017}
}
Comments
The presentation has been polished. We have added the remark that any projective variety can be realized by using matrix pencils of square matrices