Summary: The Fiedler matrices are a large class of companion matrices that include the well-known Frobenius companion matrix. The Fiedler matrices are part of a larger class of companion matrices that can be characterized by a Hessenberg form. We demonstrate that the Hessenberg form of the Fiedler companion matrices provides a straight-forward way to compare the condition numbers of these matrices. We also show that there are other companion matrices which can provide a much smaller condition number than any Fiedler companion matrix. We finish by exploring the condition number of a class of matrices obtained from perturbing a Frobenius companion matrix while preserving the characteristic polynomial.\looseness -1
[6] Garnett, C., Shader, B. L., Shader, C. L., Driessche, P. van den: Characterization of a family of generalized companion matrices. Linear Algebra Appl. 498 (2016), 360-365. DOI 10.1016/j.laa.2015.07.031 | MR 3478567 | Zbl 1371.15019