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arXiv 2401.10486math.PRmath.CO
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随机图控制数的两点集中性

Two-Point Concentration of the Domination Number of Random Graphs

Tom Bohman, Lutz Warnke, Emily Zhu

AI总结:

本文研究了随机图控制数的两点集中性,证明了在特定边概率范围内集中于两个值,并反驳了Glebov等人的猜想,通过适应Janson不等式证明泊松型近似。

摘要:

我们证明了边概率为p的二项随机图G_{n,p}的控制数在p \ge n^{-2/3+\eps}时集中于两个值,而在一般p \le n^{-2/3}时不集中于两个值。这反驳了Glebov、Liebenau和Szabo的猜想,他们证明了p \ge n^{-1/2+\eps}时的两点集中性,并猜想两点集中性在p \ll n^{-1/2}时失效。我们主要结果的证明需要对随机二部图没有孤立顶点的概率进行泊松型近似,这在标准工具不可用的情况下(因为孤立顶点的期望数量相对较大)是必要的。我们通过将Janson不等式的证明适应于这种情况来实现这种近似,这种适应可能具有更广泛的意义。

英文摘要:

We show that the domination number of the binomial random graph G_{n,p} with edge-probability p is concentrated on two values for p \ge n^{-2/3+\eps}, and not concentrated on two values for general p \le n^{-2/3}. This refutes a conjecture of Glebov, Liebenau and Szabo, who showed two-point concentration for p \ge n^{-1/2+\eps}, and conjectured that two-point concentration fails for p \ll n^{-1/2}. The proof of our main result requires a Poisson type approximation for the probability that a random bipartite graph has no isolated vertices, in a regime where standard tools are unavailable (as the expected number of isolated vertices is relatively large). We achieve this approximation by adapting the proof of Janson's inequality to this situation, and this adaptation may be of broader interest.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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