Robust density estimation over star-shaped density classes

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Liu, Xiaolong, Neykov, Matey
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866910788109729792
author Liu, Xiaolong
Neykov, Matey
author_facet Liu, Xiaolong
Neykov, Matey
contents We establish a novel criterion for comparing the performance of two densities, $g_1$ and $g_2$, within the context of corrupted data. Utilizing this criterion, we propose an algorithm to construct a density estimator within a star-shaped density class, $\mathcal{F}$, under conditions of data corruption. We proceed to derive the minimax upper and lower bounds for density estimation across this star-shaped density class, characterized by densities that are uniformly bounded above and below (in the sup norm), in the presence of adversarially corrupted data. Specifically, we assume that a fraction $ε\leq \frac{1}{3}$ of the $N$ observations are arbitrarily corrupted. We obtain the minimax upper bound $\max\{ τ_{\overline{J}}^2, ε\} \wedge d^2$. Under certain conditions, we obtain the minimax risk, up to proportionality constants, under the squared $L_2$ loss as $$ \max\left\{ τ^{*2} \wedge d^2, ε\wedge d^2 \right\}, $$ where $τ^* := \sup\left\{ τ: Nτ^2 \leq \log \mathcal{M}_{\mathcal{F}}^{\text{loc}}(τ, c) \right\}$ for a sufficiently large constant $c$. Here, $\mathcal{M}_{\mathcal{F}}^{\text{loc}}(τ, c)$ denotes the local entropy of the set $\mathcal{F}$, and $d$ is the $L_2$ diameter of $\mathcal{F}$.
format Preprint
id arxiv_https___arxiv_org_abs_2501_10025
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Robust density estimation over star-shaped density classes
Liu, Xiaolong
Neykov, Matey
Statistics Theory
Machine Learning
We establish a novel criterion for comparing the performance of two densities, $g_1$ and $g_2$, within the context of corrupted data. Utilizing this criterion, we propose an algorithm to construct a density estimator within a star-shaped density class, $\mathcal{F}$, under conditions of data corruption. We proceed to derive the minimax upper and lower bounds for density estimation across this star-shaped density class, characterized by densities that are uniformly bounded above and below (in the sup norm), in the presence of adversarially corrupted data. Specifically, we assume that a fraction $ε\leq \frac{1}{3}$ of the $N$ observations are arbitrarily corrupted. We obtain the minimax upper bound $\max\{ τ_{\overline{J}}^2, ε\} \wedge d^2$. Under certain conditions, we obtain the minimax risk, up to proportionality constants, under the squared $L_2$ loss as $$ \max\left\{ τ^{*2} \wedge d^2, ε\wedge d^2 \right\}, $$ where $τ^* := \sup\left\{ τ: Nτ^2 \leq \log \mathcal{M}_{\mathcal{F}}^{\text{loc}}(τ, c) \right\}$ for a sufficiently large constant $c$. Here, $\mathcal{M}_{\mathcal{F}}^{\text{loc}}(τ, c)$ denotes the local entropy of the set $\mathcal{F}$, and $d$ is the $L_2$ diameter of $\mathcal{F}$.
title Robust density estimation over star-shaped density classes
topic Statistics Theory
Machine Learning
url https://arxiv.org/abs/2501.10025