arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.06484math.GR
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有限群的Chebotarev不变量的一个上界

An upper bound on the Chebotarev invariant of a finite group

Andrea Lucchini, Gareth Tracey

摘要:

如果集合$\{g_1^{x_1}, \ldots, g_d^{x_d}\}$对$x_i \in G$的每个选择都生成$G$,则有限群$G$的子集$\{g_1, \ldots , g_d\}$总是生成$G$。$G$的Chebotarev不变量$C(G)$是随机变量$n$的期望值,该期望值最小,满足$n$随机选择的$G$元素总是生成$G$的要求。第一作者最近证明了对于某些绝对常数$β$,$C(G)\le β\sqrt{|G|}$.在本文中,我们表明,当$G$是可溶的,那么$β$是最多$5/3$。我们还表明,这是最好的可能。此外,我们表明,在一般情况下,对于每个$ε>0$存在一个常数$c_ε$,使$C(G)\le (1+ε)\sqrt{|G|}+c_ε$。

英文摘要:

A subset $\{g_1, \ldots , g_d\}$ of a finite group $G$ invariably generates $G$ if the set $\{g_1^{x_1}, \ldots, g_d^{x_d}\}$ generates $G$ for every choice of $x_i \in G$. The Chebotarev invariant $C(G)$ of $G$ is the expected value of the random variable $n$ that is minimal subject to the requirement that $n$ randomly chosen elements of $G$ invariably generate $G$. The first author recently showed that $C(G)\le β\sqrt{|G|}$ for some absolute constant $β$. In this paper we show that, when $G$ is soluble, then $β$ is at most $5/3$. We also show that this is best possible. Furthermore, we show that, in general, for each $ε>0$ there exists a constant $c_ε$ such that $C(G)\le (1+ε)\sqrt{|G|}+c_ε$.

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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