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arXiv 1904.01263math.PR
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关于Erdös-Rènyi随机图的一些估计

On some estimates for Erdös-Rènyi random graph

Nikolay Kazimirow

摘要:

我们考虑一个随机图$G(n,p)$中的若干个分支$ν_n$,其中每个分支的边的概率等于$p$,该图的顶点是$n$。通过与特殊的生成函数的操作,我们显示了下一个渐近关系的阶乘时刻的$ν_n$:$$ \mathsf{E}(ν_n-1)^{\underline s} = (1+o(1))\left( \frac 1p \sum\limits_{k=1}^\infty\frac{k^{k-2}}{k!}(npq^n)^k\right)^s + o(1) $$作为$n$趋于$\infty$和$q=1-p$。以下不等式成立:$$ 1-2nq^{n-1} \le p_n\le\frac{1}{nq^n}, $$ $$ 1-\frac{1}{nq^n}\le pi_n\le nq^{n-1}, $$其中$p_n$是$G(n,p)$连通的概率,$pi_n$是$G(n,p)$有孤立顶点的概率。

英文摘要:

We consider a number $ν_n$ of components in a random graph $G(n,p)$ with $n$ vertices, where the probability of an edge is equal to $p$. By operating with special generating functions we shows the next asymptotic relation for factorial moments of $ν_n$: $$ \mathsf{E}(ν_n-1)^{\underline s} = (1+o(1))\left( \frac 1p \sum\limits_{k=1}^\infty\frac{k^{k-2}}{k!}(npq^n)^k\right)^s + o(1) $$ as $n$ tends to $\infty$ and $q=1-p$. And the following inequations hold: $$ 1-2nq^{n-1} \le p_n\le\frac{1}{nq^n}, $$ $$ 1-\frac{1}{nq^n}\le pi_n\le nq^{n-1}, $$ where $p_n$ is the probability that $G(n,p)$ is connected and $pi_n$ is the probability that $G(n,p)$ has an isolated vertex.

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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