About the spectra of a real nonnegative matrix and its signings

For a complex matrix \(M\), we denote by \(\operatorname{Sp}(M)\) the spectrum of \(M\) and by \(|M|\) its absolute value, that is the matrix obtained from \(M\) by replacing each entry of \(M\) by its absolute value. Let \(A\) be a nonnegative real matrix, we call a signing of \(A\) every real matr...

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Date:2021
Main Authors: Attas, K., Boussaïri, A., Zaidi, M.
Format: Article
Language:English
Published: Lugansk National Taras Shevchenko University 2021
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Online Access:https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1461
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Journal Title:Algebra and Discrete Mathematics

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Algebra and Discrete Mathematics
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author Attas, K.
Boussaïri, A.
Zaidi, M.
author_facet Attas, K.
Boussaïri, A.
Zaidi, M.
author_sort Attas, K.
baseUrl_str
collection OJS
datestamp_date 2021-11-09T03:53:16Z
description For a complex matrix \(M\), we denote by \(\operatorname{Sp}(M)\) the spectrum of \(M\) and by \(|M|\) its absolute value, that is the matrix obtained from \(M\) by replacing each entry of \(M\) by its absolute value. Let \(A\) be a nonnegative real matrix, we call a signing of \(A\) every real matrix \(B\) such that \(|B| =A\). In this paper, we characterize the set of all signings of \(A\) such that \(\operatorname{Sp}(B)=\alpha \operatorname{Sp}(A)\) where \(\alpha\) is a complex unit number. Our motivation comes from some recent results about the relationship between the spectrum of a graph and the skew spectra of its orientations.
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language English
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spelling admjournalluguniveduua-article-14612021-11-09T03:53:16Z About the spectra of a real nonnegative matrix and its signings Attas, K. Boussaïri, A. Zaidi, M. spectra, digraphs, nonnegative matrices, irreducible matrices 05C20, 05C50 For a complex matrix \(M\), we denote by \(\operatorname{Sp}(M)\) the spectrum of \(M\) and by \(|M|\) its absolute value, that is the matrix obtained from \(M\) by replacing each entry of \(M\) by its absolute value. Let \(A\) be a nonnegative real matrix, we call a signing of \(A\) every real matrix \(B\) such that \(|B| =A\). In this paper, we characterize the set of all signings of \(A\) such that \(\operatorname{Sp}(B)=\alpha \operatorname{Sp}(A)\) where \(\alpha\) is a complex unit number. Our motivation comes from some recent results about the relationship between the spectrum of a graph and the skew spectra of its orientations. Lugansk National Taras Shevchenko University 2021-11-09 Article Article Peer-reviewed Article application/pdf https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1461 10.12958/adm1461 Algebra and Discrete Mathematics; Vol 32, No 1 (2021) 2415-721X 1726-3255 en https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1461/pdf https://admjournal.luguniv.edu.ua/index.php/adm/article/downloadSuppFile/1461/584 Copyright (c) 2021 Algebra and Discrete Mathematics
spellingShingle spectra
digraphs
nonnegative matrices
irreducible matrices
05C20
05C50
Attas, K.
Boussaïri, A.
Zaidi, M.
About the spectra of a real nonnegative matrix and its signings
title About the spectra of a real nonnegative matrix and its signings
title_full About the spectra of a real nonnegative matrix and its signings
title_fullStr About the spectra of a real nonnegative matrix and its signings
title_full_unstemmed About the spectra of a real nonnegative matrix and its signings
title_short About the spectra of a real nonnegative matrix and its signings
title_sort about the spectra of a real nonnegative matrix and its signings
topic spectra
digraphs
nonnegative matrices
irreducible matrices
05C20
05C50
topic_facet spectra
digraphs
nonnegative matrices
irreducible matrices
05C20
05C50
url https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1461
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