Product of two matrices similar to companion matrices over sufficiently large fields
In this note, we prove that a square matrix of size $n$ over a field containing at least $2n$ elements can be expressed as the product of two matrices similar to companion matrices, that is to say matrices with the same minimal and characteristic polynomial, if and only if the rank of $A$ is greater than $n-2$, using only elementary facts. We will also give some partial results valid over smaller fields.
Authors
- Flavien Mabilat (ORCID: https://orcid.org/0009-0005-9350-747X)
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2026-06-18
- DOI
- https://doi.org/10.5281/zenodo.20744913
- Primary Topic
- Matrix Theory and Algorithms
- Type
- preprint