UNBALANCED UNICYCLIC AND BICYCLIC GRAPHS WITH EXTREMAL SPECTRAL RADIUS

被引：7

作者：

Belardo, Francesco ^{[1
]}

Brunetti, Maurizio ^{[1
]}

Ciampella, Adriana ^{[1
]}

机构：

[1] Univ Napoli Federico II, Dipartimento Matemat & Applicaz R Caccioppoli, I-80126 Naples, Italy

来源：

CZECHOSLOVAK MATHEMATICAL JOURNAL | 2021年 / 71卷 / 02期

关键词：

signed graph; spectral radius; bicyclic graph; LARGEST EIGENVALUE; INDEX;

D O I：

10.21136/CMJ.2020.0403-19

中图分类号：

O1 [数学];

学科分类号：

0701 ; 070101 ;

摘要：

A signed graph Gamma is a graph whose edges are labeled by signs. If Gamma has n vertices, its spectral radius is the number rho(Gamma) := max{vertical bar lambda(i)(Gamma)vertical bar : 1 <= i <= n}, where lambda(1)(Gamma) >= ... >= lambda(n)(Gamma) are the eigenvalues of the signed adjacency matrix A(Gamma). Here we determine the signed graphs achieving the minimal or the maximal spectral radius in the classes U-n and B-n of unbalanced unicyclic graphs and unbalanced bicyclic graphs, respectively.

引用

收藏

页码：417 / 433

页数：17

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