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arXiv · 2411.11557

Maxima of the $Q$-index of 2 leaves-free graphs with given size

Yuxiang Liu·Ligong Wang·Xiaolong Jia
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Abstract

The $Q$-index of graph $G$ is the largest eigenvalue of the signless Laplacian matrix of $G$. Wang [Discrete Appl. Math. 356(2024)] proved the sharp upper bounds on the $Q$-index of leaf-free graphs with given size and characterized the corresponding extremal graphs. A graph is $2$ leaves-free if it has no two pendent vertices. In this paper, we give sharp upper bounds on the $Q$-index of 2 leaves-free graphs with given size and characterize the corresponding extremal graphs.

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Yuxiang Liu, Ligong Wang, Xiaolong Jia. 2024-11-18. Maxima of the $Q$-index of 2 leaves-free graphs with given size. https://arxiv.org/abs/2411.11557

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