Spectral radius and matchings in graphs
A perfect matching in a graph G is a set of disjoint edges covering all vertices of G. Let ρ(G) be the spectral radius of a graph G, and let θ(n) be the largest root of x3−(n−4)x2−(n−1)x+2(n−4)=0. In this paper, we prove that for a positive even integer n≥8 or n=4, if G is an n-vertex graph with ρ(G...
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Published in | Linear algebra and its applications Vol. 614; pp. 316 - 324 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier Inc
01.04.2021
American Elsevier Company, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | A perfect matching in a graph G is a set of disjoint edges covering all vertices of G. Let ρ(G) be the spectral radius of a graph G, and let θ(n) be the largest root of x3−(n−4)x2−(n−1)x+2(n−4)=0. In this paper, we prove that for a positive even integer n≥8 or n=4, if G is an n-vertex graph with ρ(G)>θ(n), then G has a perfect matching; for n=6, if ρ(G)>1+332, then G has a perfect matching. It is sharp for every positive even integer n≥4 in the sense that there are graphs H with ρ(H)=θ′(n) and no perfect matching, where θ′(n)=θ(n) if n=4 or n≥8 and θ′(6)=1+332. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 |
ISSN: | 0024-3795 1873-1856 |
DOI: | 10.1016/j.laa.2020.06.004 |