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arXiv 1904.04417math.STstat.TH
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收缩先验下的超高维多元后收缩率

Ultra High-dimensional Multivariate Posterior Contraction Rate Under Shrinkage Priors

Ruoyang Zhang, Malay Ghosh

摘要:

近年来,从贝叶斯的角度来看,收缩先验在高维数据分析中受到了广泛的关注。与广泛使用的spike-and-slab先验相比,收缩先验具有更好的计算效率。但是,在许多情况下,不确定度量化中的重要理论性质,特别是后验收缩率并不成立。本文将全局-局部收缩先验应用于协方差阵未知的高维多元线性回归。我们证明了当先验高度集中在零附近且具有厚尾时,系数矩阵和协方差阵的后验收缩率接近最优。当特征数p比样本量n增长得更快时,我们的结果成立,这在现代数据分析中具有很大的意义。我们证明了一类容易实现的规模混合正常先验满足的主要定理的条件。

英文摘要:

In recent years, shrinkage priors have received much attention in high-dimensional data analysis from a Bayesian perspective. Compared with widely used spike-and-slab priors, shrinkage priors have better computational efficiency. But the theoretical properties, especially posterior contraction rate, which is important in uncertainty quantification, are not established in many cases. In this paper, we apply global-local shrinkage priors to high-dimensional multivariate linear regression with unknown covariance matrix. We show that when the prior is highly concentrated near zero and has heavy tail, the posterior contraction rates for both coefficients matrix and covariance matrix are nearly optimal. Our results hold when number of features p grows much faster than the sample size n, which is of great interest in modern data analysis. We show that a class of readily implementable scale mixture of normal priors satisfies the conditions of the main theorem.

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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