Eigenvalues of laplacian matrices of the cycles with one negative-weighted edge

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Grudsky, S. M., Maximenko, E. A., Soto-González, A.
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866913655029760000
author Grudsky, S. M.
Maximenko, E. A.
Soto-González, A.
author_facet Grudsky, S. M.
Maximenko, E. A.
Soto-González, A.
contents We study the individual behavior of the eigenvalues of the laplacian matrices of the cyclic graph of order $n$, where one edge has weight $α\in\mathbb{C}$, with $\operatorname{Re}(α)<0$, and all the others have weights $1$. This paper is a sequel of a previous one where we considered $\operatorname{Re}(α) \in[0,1]$ (Eigenvalues of laplacian matrices of the cycles with one weighted edge, Linear Algebra Appl. 653, 2022, 86--115). We prove that for $\operatorname{Re}(α)<0$ and $n>\operatorname{Re}(α-1)/\operatorname{Re}(α)$, one eigenvalue is negative while the others belong to $[0,4]$ and are distributed as the function $x\mapsto 4\sin^2(x/2)$. Additionally, we prove that as $n$ tends to $\infty$, the outlier eigenvalue converges exponentially to $4\operatorname{Re}(α)^2/(2\operatorname{Re}(α)-1)$. We give exact formulas for the half of the inner eigenvalues, while for the others we justify the convergence of Newton's method and fixed-point iteration method. We find asymptotic expansions, as $n$ tends to $\infty$, both for the eigenvalues belonging to $[0,4]$ and the outlier. We also compute the eigenvectors and their norms.
format Preprint
id arxiv_https___arxiv_org_abs_2308_07514
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Eigenvalues of laplacian matrices of the cycles with one negative-weighted edge
Grudsky, S. M.
Maximenko, E. A.
Soto-González, A.
Spectral Theory
Rings and Algebras
05C50, 47B36, 15A18, 15B05, 41A60, 65F15
We study the individual behavior of the eigenvalues of the laplacian matrices of the cyclic graph of order $n$, where one edge has weight $α\in\mathbb{C}$, with $\operatorname{Re}(α)<0$, and all the others have weights $1$. This paper is a sequel of a previous one where we considered $\operatorname{Re}(α) \in[0,1]$ (Eigenvalues of laplacian matrices of the cycles with one weighted edge, Linear Algebra Appl. 653, 2022, 86--115). We prove that for $\operatorname{Re}(α)<0$ and $n>\operatorname{Re}(α-1)/\operatorname{Re}(α)$, one eigenvalue is negative while the others belong to $[0,4]$ and are distributed as the function $x\mapsto 4\sin^2(x/2)$. Additionally, we prove that as $n$ tends to $\infty$, the outlier eigenvalue converges exponentially to $4\operatorname{Re}(α)^2/(2\operatorname{Re}(α)-1)$. We give exact formulas for the half of the inner eigenvalues, while for the others we justify the convergence of Newton's method and fixed-point iteration method. We find asymptotic expansions, as $n$ tends to $\infty$, both for the eigenvalues belonging to $[0,4]$ and the outlier. We also compute the eigenvectors and their norms.
title Eigenvalues of laplacian matrices of the cycles with one negative-weighted edge
topic Spectral Theory
Rings and Algebras
05C50, 47B36, 15A18, 15B05, 41A60, 65F15
url https://arxiv.org/abs/2308.07514