Xiao-Dong Zhang

activity

20242026

collaborators

4 papers

math.CO2026

Positive and negative 3-energies of graphs

Zhengbo Chen, Zhouningxin Wang, Xiao-Dong Zhang

For a simple graph $G$ with $n$ vertices, let $A_{G}$ denote the adjacency matrix of $G$ , and let $λ_{1} (G) \geq λ_{2} (G) \geq \dots \geq λ_{n} (G)$ be its eigenvalues. For an integer $p \g…

math.CO2026

Turán extremal graphs vs. Signless Laplacian spectral Turán extremal graphs

Ming-Zhu Chen, Ya-Lei Jin, Peng-Li Zhang +1

Let $F$ be a graph with chromatic number $χ (F) = r + 1$ . Denote by $e x (n, F)$ and $E x (n, F)$ the Turán number and the set of all extremal graphs for $F$ , respectively. In addition, $…

math.CO2025

Generalized Turan number with given size

Yan Wang, Yue Xu, Jiasheng Zeng +1

Generalized Turán problem with given size, denoted as $mex (m, K_{r}, F)$ , determines the maximum number of $K_{r}$ -copies in an $F$ -free graph with $m$ edges. We prove that for…

math.CO2024

Dense halves in balanced 2-partition of K4-free graphs

Yue Xu, Xiao-Dong Zhang

A balanced 2-partition of a graph is a bipartition $A, A^{c}$ of $V (G)$ such that $∣ A ∣ = ∣ A^{c} ∣$ . Balogh, Clemen, and Lidický conjectured that for every $K_{4}$ -free graph on $n$ (even) ve…