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arXiv 2101.05099math.STmath.PRstat.TH
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脊柱结构树的最大似然估计

Maximum likelihood estimation for spinal-structured trees

Romain Azaïs, Benoît Henry

AI总结:

针对类型不可观测的脊柱结构两类型 Galton–Watson 树,论文研究出生分布的最大似然估计,并给出可区分性与可估计性的增长率—散度条件。

摘要:

我们研究了在类型未被观测的多类型 Galton–Watson 树(MGW)中估计出生分布(BD)问题的若干方面。更具体地说,我们考虑一类称为脊柱结构树的两类型 MGW。这种树的特征是存在一条由特殊个体组成的脊柱,这些个体的 BD 为 $ν$,不同于树中的其他个体(称为正常个体,其 BD 记为 $μ$)。在本文中,我们表明,即使在这样一种高度结构化的两类型总体中,我们区分这两种类型并估计 $μ$ 和 $ν$ 的能力,也受到总体增长率与 $μ$、$ν$ 相似性之间权衡的制约。事实上,如果增长率过大,在对正常个体进行抽样时很可能观测到大偏差事件,从而使我们无法将他们与特殊个体区分开来。粗略地说,当 $r<\mathfrak{D}(μ,ν)$ 时,我们的方法可以成功,其中 $r$ 是总体的指数增长率,而 $\mathfrak{D}$ 是衡量 $μ$ 与 $ν$ 之间不相似性的一种散度。

英文摘要:

We investigate some aspects of the problem of the estimation of birth distributions (BD) in multi-type Galton-Watson trees (MGW) with unobserved types. More precisely, we consider two-type MGW called spinal-structured trees. This kind of tree is characterized by a spine of special individuals whose BD $ν$ is different from the other individuals in the tree (called normal whose BD is denoted $μ$). In this work, we show that even in such a very structured two-type population, our ability to distinguish the two types and estimate $μ$ and $ν$ is constrained by a trade-off between the growth-rate of the population and the similarity of $μ$ and $ν$. Indeed, if the growth-rate is too large, large deviations events are likely to be observed in the sampling of the normal individuals preventing us to distinguish them from special ones. Roughly speaking, our approach succeeds if $r<\mathfrak{D}(μ,ν)$ where $r$ is the exponential growth-rate of the population and $\mathfrak{D}$ is a divergence measuring the dissimilarity between $μ$ and $ν$.

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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