English

All limit points of the largest roots of matching polynomials are determined

Combinatorics 2026-06-26 v1

Abstract

The largest matching root μ(G)\mu(G) of a graph GG is that of its matching polynomial. In this paper, all limit points of the largest matching roots of graphs are determined. More precisely, we identify the limit points of the largest matching roots of graphs less than τ12+τ12\tau^{\frac{1}{2}}+\tau^{-\frac{1}{2}}. For any γτ12+τ12\gamma \geq \tau^{\frac{1}{2}}+\tau^{-\frac{1}{2}} with τ=5+12\tau=\frac{\sqrt{5}+1}{2}, there exists a graph sequence {GiiN}\{G_i\, |\, i\in \mathbb{N}\} such that limiμ(Gi)=γ\lim\limits_{i \rightarrow \infty}\mu(G_i)=\gamma.

Keywords

Cite

@article{arxiv.2606.28162,
  title  = {All limit points of the largest roots of matching polynomials are determined},
  author = {Zhaoxi Li and Shi-Mei Ma and Jianfeng Wang and Weifan Wang},
  journal= {arXiv preprint arXiv:2606.28162},
  year   = {2026}
}