发表机构
Harvard Chan School of Public Health(哈佛陈曾熙公共卫生学院)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
针对比例高维线性模型,在密集机制下研究线性泛函估计,提出Bocca估计器,通过复围道积分组合经验校准预解式,达到极小极大最优速率。
AI 中文摘要
我们研究了在随机设计线性模型中,当γ=p/n∈(1,∞)且处于密集机制下,设计协方差未知,且回归向量和精度矩阵均不假设稀疏时,线性泛函的估计问题。假设设计协方差的谱属于[ℓ,L],我们建立了线性泛函的极小极大均方误差率,其阶为n^{-α(κ,γ)},其中指数α(κ,γ)具有显式的椭圆积分表示,并且当κ>1且γ>1时,α(κ,γ)<1。我们提出了Bocca估计器,该估计器通过复围道积分组合经验校准的预解式,以达到最优速率。
英文摘要
We study estimation of a linear functional in random-design linear models when $γ=p/n \in (1, \infty)$ under the dense regime where the design covariance is unknown, and neither the regression vector nor the precision matrix is assumed sparse. Suppose the spectrum of the design covariance belongs to $[\ell,L]$, we establish the minimax mean squared rate for the linear functional has the order $n^{-α(κ,γ)}$, where the exponent $α(κ,γ)$ has an explicit elliptic-integral representation and $α(κ,γ) < 1$ when both $κ> 1$ and $γ> 1$. We propose the Bocca estimator, which combines empirically calibrated resolvents through a complex contour integral to attain the optimal rate.