Adaptive exact recovery in sparse nonparametric models

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Hauptverfasser: Stepanova, Natalia, Turcicova, Marie
Format: Preprint
Veröffentlicht: 2024
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author Stepanova, Natalia
Turcicova, Marie
author_facet Stepanova, Natalia
Turcicova, Marie
contents We observe an unknown regression function of $d$ variables $f(\boldsymbol{t})$, $\boldsymbol{t} \in[0,1]^d$, in the Gaussian white noise model of intensity $\varepsilon>0$. We assume that the function $f$ is regular and that it is a sum of $k$-variate functions, where $k$ varies from $1$ to $s$ ($1\leq s\leq d$). These functions are unknown to us and only few of them are nonzero. In this article, we address the problem of identifying the nonzero components of $f$ in the case when $d=d_\varepsilon\to \infty$ as $\varepsilon\to 0$ and $s$ is either fixed or $s=s_\varepsilon\to \infty$, $s=o(d)$ as $\varepsilon\to \infty$. This may be viewed as a variable selection problem. We derive the conditions when exact variable selection in the model at hand is possible and provide a selection procedure that achieves this type of selection. The procedure is adaptive to a degree of model sparsity described by the sparsity parameter $β\in(0,1)$. We also derive conditions that make the exact variable selection impossible. Our results augment previous work in this area.
format Preprint
id arxiv_https___arxiv_org_abs_2411_04320
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Adaptive exact recovery in sparse nonparametric models
Stepanova, Natalia
Turcicova, Marie
Statistics Theory
62G08 (Primary), 62H12, 62G20 (Secondary)
We observe an unknown regression function of $d$ variables $f(\boldsymbol{t})$, $\boldsymbol{t} \in[0,1]^d$, in the Gaussian white noise model of intensity $\varepsilon>0$. We assume that the function $f$ is regular and that it is a sum of $k$-variate functions, where $k$ varies from $1$ to $s$ ($1\leq s\leq d$). These functions are unknown to us and only few of them are nonzero. In this article, we address the problem of identifying the nonzero components of $f$ in the case when $d=d_\varepsilon\to \infty$ as $\varepsilon\to 0$ and $s$ is either fixed or $s=s_\varepsilon\to \infty$, $s=o(d)$ as $\varepsilon\to \infty$. This may be viewed as a variable selection problem. We derive the conditions when exact variable selection in the model at hand is possible and provide a selection procedure that achieves this type of selection. The procedure is adaptive to a degree of model sparsity described by the sparsity parameter $β\in(0,1)$. We also derive conditions that make the exact variable selection impossible. Our results augment previous work in this area.
title Adaptive exact recovery in sparse nonparametric models
topic Statistics Theory
62G08 (Primary), 62H12, 62G20 (Secondary)
url https://arxiv.org/abs/2411.04320