A note on eigenvalues of signed graphs

被引:3
|
作者
Sun, Gaoxing [1 ]
Liu, Feng [2 ]
Lan, Kaiyang [2 ]
机构
[1] Henan Normal Univ, Coll Math & Informat Sci, Xinxiang 453007, Peoples R China
[2] Fuzhou Univ, Ctr Discrete Math, Fuzhou 350003, Fujian, Peoples R China
关键词
Signed graph; Eigenvalue; Balanced clique number; SPECTRAL-RADIUS; BOUNDS; NUMBERS; CLIQUE;
D O I
10.1016/j.laa.2022.07.010
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
Suppose that sigma is a signed graph with n vertices and m edges. Let lambda 1 > lambda 2 > . . . > lambda n be the eigenvalues of sigma. A signed graph is called balanced if each of its cycles contains an even number of negative edges, and unbalanced otherwise. Let wb be the balanced clique number of sigma, which is the maximum order of a balanced complete subgraph of sigma. In this paper, we prove that lambda 1 <= root 2 omega b - 1/omega bm. This inequality extends a conjecture of ordinary graphs, which was confirmed by Nikiforov (2002) [8], to the signed case. In addition, we completely characterize the signed graphs with -1 < lambda 2 < 0.(c) 2022 Elsevier Inc. All rights reserved.
引用
收藏
页码:125 / 131
页数:7
相关论文
共 50 条
  • [1] Note on the normalized Laplacian eigenvalues of signed graphs
    Li, Hong-Hai
    Li, Jiong-Sheng
    [J]. AUSTRALASIAN JOURNAL OF COMBINATORICS, 2009, 44 : 153 - 162
  • [2] On the Aα-Eigenvalues of Signed Graphs
    Pasten, Germain
    Rojo, Oscar
    Medina, Luis
    [J]. MATHEMATICS, 2021, 9 (16)
  • [3] On the Eigenvalues of Some Signed Graphs
    Souri, M.
    Heydari, F.
    Maghasedi, M.
    [J]. IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY TRANSACTION A-SCIENCE, 2021, 45 (02): : 635 - 639
  • [4] On the Laplacian eigenvalues of signed graphs
    Hou, YP
    Li, JS
    Pan, YL
    [J]. LINEAR & MULTILINEAR ALGEBRA, 2003, 51 (01): : 21 - 30
  • [5] On the Eigenvalues of Some Signed Graphs
    M. Souri
    F. Heydari
    M. Maghasedi
    [J]. Iranian Journal of Science and Technology, Transactions A: Science, 2021, 45 : 635 - 639
  • [6] Walks and eigenvalues of signed graphs
    Stanic, Zoran
    [J]. SPECIAL MATRICES, 2023, 11 (01):
  • [7] On the eigenvalues of signed complete graphs
    Akbari, S.
    Dalvandi, S.
    Heydari, F.
    Maghasedi, M.
    [J]. LINEAR & MULTILINEAR ALGEBRA, 2019, 67 (03): : 433 - 441
  • [8] The main eigenvalues of signed graphs
    Akbari, S.
    Franca, F. A. M.
    Ghasemian, E.
    Javarsineh, M.
    de Lima, L. S.
    [J]. LINEAR ALGEBRA AND ITS APPLICATIONS, 2021, 614 : 270 - 280
  • [9] Spectra of signed graphs with two eigenvalues
    Stanic, Zoran
    [J]. APPLIED MATHEMATICS AND COMPUTATION, 2020, 364
  • [10] Signed Graphs with at Most Three Eigenvalues
    Ramezani, Farzaneh
    Rowlinson, Peter
    Stanic, Zoran
    [J]. CZECHOSLOVAK MATHEMATICAL JOURNAL, 2022, 72 (01) : 59 - 77