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arXiv · 2304.03046

On the $A_\alpha$-spectral radius of graphs without linear forests

Ming-Zhu Chen·A-Ming Liu·Xiao-Dong Zhang
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Abstract

Let $A(G)$ and $D(G)$ be the adjacency and degree matrices of a simple graph $G$ on $n$ vertices, respectively. The \emph{$A_\alpha$-spectral radius} of $G$ is the largest eigenvalue of $A_\alpha (G)=\alpha D(G)+(1-\alpha)A(G)$ for a real number $\alpha \in[0,1]$. In this paper, for $\alpha \in (0,1)$, we obtain a sharp upper bound for the $A_\alpha$-spectral radius of graphs on $n$ vertices without a subgraph isomorphic to a liner forest for $n$ large enough and characterize all graphs which attain the upper bound. As a result, we completely obtain the maximum signless Laplacian spectral radius of graphs on $n$ vertices without a subgraph isomorphic to a liner forest for $n$ large enough.

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Ming-Zhu Chen, A-Ming Liu, Xiao-Dong Zhang. 2023-04-06. On the $A_\alpha$-spectral radius of graphs without linear forests. https://arxiv.org/abs/2304.03046

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