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Bibliographic Details
Main Authors: Sinha, Kaushik, Tosh, Christopher
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.06175
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author Sinha, Kaushik
Tosh, Christopher
author_facet Sinha, Kaushik
Tosh, Christopher
contents Expand-and-sparsify representations are a class of theoretical models that capture sparse representation phenomena observed in the sensory systems of many animals. At a high level, these representations map an input $x \in \mathbb{R}^d$ to a much higher dimension $m \gg d$ via random linear projections before zeroing out all but the $k \ll m$ largest entries. The result is a $k$-sparse vector in $\{0,1\}^m$. We study the suitability of this representation for two fundamental statistical problems: density estimation and mode estimation. For density estimation, we show that a simple linear function of the expand-and-sparsify representation produces an estimator with minimax-optimal $\ell_{\infty}$ convergence rates. In mode estimation, we provide simple algorithms on top of our density estimator that recover single or multiple modes at optimal rates up to logarithmic factors under mild conditions.
format Preprint
id arxiv_https___arxiv_org_abs_2602_06175
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Optimal rates for density and mode estimation with expand-and-sparsify representations
Sinha, Kaushik
Tosh, Christopher
Statistics Theory
Artificial Intelligence
Machine Learning
Expand-and-sparsify representations are a class of theoretical models that capture sparse representation phenomena observed in the sensory systems of many animals. At a high level, these representations map an input $x \in \mathbb{R}^d$ to a much higher dimension $m \gg d$ via random linear projections before zeroing out all but the $k \ll m$ largest entries. The result is a $k$-sparse vector in $\{0,1\}^m$. We study the suitability of this representation for two fundamental statistical problems: density estimation and mode estimation. For density estimation, we show that a simple linear function of the expand-and-sparsify representation produces an estimator with minimax-optimal $\ell_{\infty}$ convergence rates. In mode estimation, we provide simple algorithms on top of our density estimator that recover single or multiple modes at optimal rates up to logarithmic factors under mild conditions.
title Optimal rates for density and mode estimation with expand-and-sparsify representations
topic Statistics Theory
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2602.06175