arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1201.4098math.PR
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极限$m$ -元搜索树分布的支持度和密度

Support and density of the limit $m$-ary search trees distribution

Brigitte Chauvin, Quansheng Liu, Nicolas Pouyanne

摘要:

$m$元搜索树的空间要求满足一个众所周知的相变:当$m\leq 26$时,二阶渐近是高斯的。当满足$m\geq 27$时,它不再是高斯的,并且出现了复值鞅的极限$W$。我们发现$W$的分布在复平面上有平方可积密度,它的支撑是整个复平面,并且它有有限的指数矩。证明是基于对分布方程$ W\egalLoi\sum_{k=1}^mV_k^λW_k$的研究,其中$V_1, ..., V_m$是$(m-1)$独立随机变量在$[0,1]$上均匀分布的间距,$W_1, ..., W_m$是W的独立拷贝,也与$(V_1, ..., V_m)$无关,$λ$是复数.

英文摘要:

The space requirements of an $m$-ary search tree satisfies a well-known phase transition: when $m\leq 26$, the second order asymptotics is Gaussian. When $m\geq 27$, it is not Gaussian any longer and a limit $W$ of a complex-valued martingale arises. We show that the distribution of $W$ has a square integrable density on the complex plane, that its support is the whole complex plane, and that it has finite exponential moments. The proofs are based on the study of the distributional equation $ W\egalLoi\sum_{k=1}^mV_k^λW_k$, where $V_1, ..., V_m$ are the spacings of $(m-1)$ independent random variables uniformly distributed on $[0,1]$, $W_1, ..., W_m$ are independent copies of W which are also independent of $(V_1, ..., V_m)$ and $λ$ is a complex number.

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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