Maximum multiplicity of matching polynomial roots and minimum path cover in general graphs
The electronic journal of combinatorics, Tome 18 (2011) no. 1
Let $G$ be a graph. It is well known that the maximum multiplicity of a root of the matching polynomial $\mu(G,x)$ is at most the minimum number of vertex disjoint paths needed to cover the vertex set of $G$. Recently, a necessary and sufficient condition for which this bound is tight was found for trees. In this paper, a similar structural characterization is proved for any graph. To accomplish this, we extend the notion of a $(\theta,G)$-extremal path cover (where $\theta$ is a root of $\mu(G,x)$) which was first introduced for trees to general graphs. Our proof makes use of the analogue of the Gallai-Edmonds Structure Theorem for general root. By way of contrast, we also show that the difference between the minimum size of a path cover and the maximum multiplicity of matching polynomial roots can be arbitrarily large.
DOI :
10.37236/525
Classification :
05C31, 05C70
Mots-clés : \((\theta , G)\)-extremal path cover, Gallai-Edmonds Structure Theorem for general root
Mots-clés : \((\theta , G)\)-extremal path cover, Gallai-Edmonds Structure Theorem for general root
@article{10_37236_525,
author = {Cheng Yeaw Ku and Kok Bin Wong},
title = {Maximum multiplicity of matching polynomial roots and minimum path cover in general graphs},
journal = {The electronic journal of combinatorics},
year = {2011},
volume = {18},
number = {1},
doi = {10.37236/525},
zbl = {1229.05121},
url = {http://geodesic.mathdoc.fr/articles/10.37236/525/}
}
TY - JOUR AU - Cheng Yeaw Ku AU - Kok Bin Wong TI - Maximum multiplicity of matching polynomial roots and minimum path cover in general graphs JO - The electronic journal of combinatorics PY - 2011 VL - 18 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.37236/525/ DO - 10.37236/525 ID - 10_37236_525 ER -
Cheng Yeaw Ku; Kok Bin Wong. Maximum multiplicity of matching polynomial roots and minimum path cover in general graphs. The electronic journal of combinatorics, Tome 18 (2011) no. 1. doi: 10.37236/525
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