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Main Authors: Chen, Rui, Tian, Songtao, Huang, Dongming, Lin, Qian, Liu, Jun S.
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2307.02777
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author Chen, Rui
Tian, Songtao
Huang, Dongming
Lin, Qian
Liu, Jun S.
author_facet Chen, Rui
Tian, Songtao
Huang, Dongming
Lin, Qian
Liu, Jun S.
contents In this paper, we prove that functional sliced inverse regression (FSIR) achieves the optimal (minimax) rate for estimating the central space in functional sufficient dimension reduction problems. First, we provide a concentration inequality for the FSIR estimator of the covariance of the conditional mean. Based on this inequality, we establish the root-$n$ consistency of the FSIR estimator of the image of covariance of the conditional mean. Second, we apply the most widely used truncated scheme to estimate the inverse of the covariance operator and identify the truncation parameter that ensures that FSIR can achieve the optimal minimax convergence rate for estimating the central space. Finally, we conduct simulations to demonstrate the optimal choice of truncation parameter and the estimation efficiency of FSIR. To the best of our knowledge, this is the first paper to rigorously prove the minimax optimality of FSIR in estimating the central space for multiple-index models and general $Y$ (not necessarily discrete).
format Preprint
id arxiv_https___arxiv_org_abs_2307_02777
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On the Optimality of Functional Sliced Inverse Regression
Chen, Rui
Tian, Songtao
Huang, Dongming
Lin, Qian
Liu, Jun S.
Statistics Theory
In this paper, we prove that functional sliced inverse regression (FSIR) achieves the optimal (minimax) rate for estimating the central space in functional sufficient dimension reduction problems. First, we provide a concentration inequality for the FSIR estimator of the covariance of the conditional mean. Based on this inequality, we establish the root-$n$ consistency of the FSIR estimator of the image of covariance of the conditional mean. Second, we apply the most widely used truncated scheme to estimate the inverse of the covariance operator and identify the truncation parameter that ensures that FSIR can achieve the optimal minimax convergence rate for estimating the central space. Finally, we conduct simulations to demonstrate the optimal choice of truncation parameter and the estimation efficiency of FSIR. To the best of our knowledge, this is the first paper to rigorously prove the minimax optimality of FSIR in estimating the central space for multiple-index models and general $Y$ (not necessarily discrete).
title On the Optimality of Functional Sliced Inverse Regression
topic Statistics Theory
url https://arxiv.org/abs/2307.02777