On the Signless Laplacian Spectral Radius of C4-free k-cyclic Graphs

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  • Departmant of Applied Mathematics, School of Science, Northwestern Polytechnical University
KONG Qi(1991-), female, native of Jincheng, Shanxi, a postgraduate student of Northwestern Polytechnical University, engages in graph theory and its application; WANG Li-gong(corresponding author)(1968-), male, native of Xinzhou, Shanxi, a professor of Northwestern Polytechnical University, Ph.D.,engages in graph theory and its applications.

Received date: 2016-12-23

  Online published: 2020-10-21

Supported by

Supported by the National Natural Science Foundation of China(11171273); Supported by the Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical University(Z2016170);

Abstract

A k-cyclic graph is a connected graph of order n and size n + k-1. In this paper, we determine the maximal signless Laplacian spectral radius and the corresponding extremal graph among all C4-free k-cyclic graphs of order n. Furthermore, we determine the first three unicycles and bicyclic, C4-free graphs whose spectral radius of the signless Laplacian is maximal. Similar results are obtained for the(combinatorial) Laplacian 

Cite this article

KONG Qi, WANG Li-gong . On the Signless Laplacian Spectral Radius of C4-free k-cyclic Graphs[J]. Chinese Quarterly Journal of Mathematics, 2017 , 32(3) : 238 -245 . DOI: 10.13371/j.cnki.chin.q.j.m.2017.03.002

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