Songnian Xu

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20232026

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2 papers · 1 filter

math.CO2025

Laplacian eigenvalue distribution and girth of graphs

Wenhao Zhen, Dein Wong, Songnian Xu

Let $G$ be a connected graph on $n$ vertices with girth $g$ . Let $m_{G} I$ denote the number of Laplacian eigenvalues of graph $G$ in an interval $I$ . In this paper, we show that if $…

math.CO2023

Near automorphisms of $G_{(n, m)}$

Songnian Xu

Let $G$ be a graph with vertex set $V (G)$ , $f$ a permutation of $V (G)$ . Define $δ_{f} (G) = ∣ d (x, y) - d (f (x), f (y)) ∣$ and $δ_{f} (G) = Σ δ_{f} (x, y)$ , where the sum is taken over all unordered pair…

Laplacian eigenvalue distribution and girth of graphs

Near automorphisms of G(n,m)​

Near automorphisms of $G_{(n, m)}$