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arXiv 2408.07534math.STmath.MGmath.PRstat.TH
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广义 Fréchet 均值的一致一致性

Uniform Consistency of Generalized Fréchet Means

University of Copenhagen(哥本哈根大学);Duke University(杜克大学);Max Planck Institute for Mathematics in the Sciences(马克斯·普朗克科学促进会数学研究所)

Andrea Aveni, Martin Bladt, Sayan Mukherjee

AI总结:

研究在具有 Heine-Borel 性质的度量空间上,通过凸损失函数定义的广义 Fréchet 均值的存在性、紧性、直径界和几乎必然一致性,并推导出损失函数类上的均匀强律。

摘要:

非线性空间上基于损失的中心概念范围从 Fréchet 均值和幂均值到几何中位数,以及在极限意义上的 Chebyshev 中心。为了在统计上使用这些汇总,首先需要一个在光滑流形之外以及固定损失选择之外仍然有效的大数定律。我们研究在具有 Heine-Borel 性质的度量空间上的广义 Fréchet 均值,通过将平方距离替换为在温和指数增长条件下的凸损失得到。我们证明了总体均值集的存在性和紧性,建立了尖锐的直径界,获得了经验 $\phi$-均值的几乎必然一致性,并推导了在损失紧类上的均匀强律。分析由确定性 argmin 原理以及单调类的 Glivenko-Cantelli 定理驱动。对于 Riemannian 对称空间上的各向同性密度,我们识别了每个严格递增损失(目标有限,包括有界鲁棒损失)下的总体 $\phi$-均值。我们还展示了该框架在球面和超度量系统发育树的多面体空间上的应用。

英文摘要:

Loss-based notions of centre on nonlinear spaces range from the Fréchet mean and power means to the geometric median and, in a limiting sense, the Chebyshev centre. To use such summaries statistically, one first needs a law of large numbers that remains valid beyond smooth manifolds and beyond a fixed choice of loss. We study generalized Fréchet means on metric spaces with the Heine--Borel property, obtained by replacing squared distance with a convex loss under a mild exponential-growth condition. We prove existence and compactness of the population mean set, establish a sharp diameter bound, obtain almost-sure consistency of empirical $ϕ$-means, and derive a uniform strong law over compact classes of losses. The analysis is driven by a deterministic argmin principle together with a Glivenko--Cantelli theorem for monotone classes. For isotropic densities on Riemannian symmetric spaces, we identify the population $ϕ$-mean for every strictly increasing loss for which the objective is finite, including bounded robust losses. We also illustrate the framework on spheres and on the polyhedral space of ultrametric phylogenetic trees.

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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