中文

图的$A_\alpha$-谱半径与完美匹配

组合数学 2021-04-12 v3

摘要

α[0,1)\alpha\in[0,1),并令GG为偶阶nn的图且nf(α)n\geq f(\alpha),其中f(α)=10f(\alpha)=10(当0α1/20\leq \alpha\leq1/2时)、f(α)=14f(\alpha)=14(当1/2<α2/31/2<\alpha\leq 2/3时)且f(α)=5/(1α)f(\alpha)=5/(1-\alpha)(当2/3<α<12/3<\alpha<1时)。本文证明了:若GGAαA_\alpha-谱半径不小于x3((α+1)n+α4)x2+(αn2+(α22α1)n2α+1)xα2n2+(5α23α+2)n10α2+15α8=0x^3 - ((\alpha + 1)n +\alpha-4)x^2 + (\alpha n^2 + (\alpha^2 - 2\alpha - 1)n - 2\alpha+1)x -\alpha^2n^2 + (5\alpha^2 - 3\alpha + 2)n - 10\alpha^2 + 15\alpha - 8=0的最大根,则GG具有完美匹配,除非G=K1(Kn32K1)G=K_1\nabla(K_{n-3}\cup 2K_1)。这推广了S. O的结果[Spectral radius and matchings in graphs, Linear Algebra Appl. 614 (2021) 316--324],该结果给出了用邻接谱半径表示图存在完美匹配的充分条件。

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引用

@article{arxiv.2007.06923,
  title  = {The $A_\alpha$-spectral radius and perfect matchings of graphs},
  author = {Yanhua Zhao and Xueyi Huang and Zhiwen Wang},
  journal= {arXiv preprint arXiv:2007.06923},
  year   = {2021}
}

备注

13 pages