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BY-NC-ND 3.0 license Open Access Published by De Gruyter Open Access December 16, 2015

Pentadiagonal Companion Matrices

  • Brydon Eastman and Kevin N. Vander Meulen EMAIL logo
From the journal Special Matrices


The class of sparse companion matrices was recently characterized in terms of unit Hessenberg matrices. We determine which sparse companion matrices have the lowest bandwidth, that is, we characterize which sparse companion matrices are permutationally similar to a pentadiagonal matrix and describe how to find the permutation involved. In the process, we determine which of the Fiedler companion matrices are permutationally similar to a pentadiagonal matrix. We also describe how to find a Fiedler factorization, up to transpose, given only its corner entries.


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Received: 2015-7-27
Accepted: 2015-10-28
Published Online: 2015-12-16
Published in Print: 2016-1-1

© 2016 Brydon Eastman et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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