Monotonicity Testing of High-Dimensional Distributions with Subcube Conditioning

TL;DR

This paper establishes nearly tight bounds for monotonicity testing of high-dimensional distributions using subcube conditioning, introducing novel isoperimetric inequalities and analyzing uniformity testing under monotonicity constraints.

Contribution

It provides the first tight bounds on subcube query complexity for high-dimensional monotonicity testing and generalizes key inequalities for real-valued functions.

Findings

Subcube query complexity for monotonicity testing is rac{n}{psilon^2}

Uniformity testing for monotone distributions has query complexity rac{\u221a{n}}{psilon^2}

Monotonicity does not significantly improve uniformity testing complexity

Abstract

We study monotonicity testing of high-dimensional distributions on $\{-1,1\}^n$ in the model of subcube conditioning, suggested and studied by Canonne, Ron, and Servedio~\cite{CRS15} and Bhattacharyya and Chakraborty~\cite{BC18}. Previous work shows that the \emph{sample complexity} of monotonicity testing must be exponential in $n$ (Rubinfeld, Vasilian~\cite{RV20}, and Aliakbarpour, Gouleakis, Peebles, Rubinfeld, Yodpinyanee~\cite{AGPRY19}). We show that the subcube \emph{query complexity} is $\tilde{\Theta}(n/\varepsilon^2)$, by proving nearly matching upper and lower bounds. Our work is the first to use directed isoperimetric inequalities (developed for function monotonicity testing) for analyzing a distribution testing algorithm. Along the way, we generalize an inequality of Khot, Minzer, and Safra~\cite{KMS18} to real-valued functions on $\{-1,1\}^n$. We also study uniformity testing of distributions that are promised to be monotone, a problem introduced by Rubinfeld, Servedio~\cite{RS09} , using subcube conditioning. We show that the query complexity is $\tilde{\Theta}(\sqrt{n}/\varepsilon^2)$. Our work proves the lower bound, which matches (up to poly-logarithmic factors) the uniformity testing upper bound for general distributions (Canonne, Chen, Kamath, Levi, Waingarten~\cite{CCKLW21}). Hence, we show that monotonicity does not help, beyond logarithmic factors, in testing uniformity of distributions with subcube conditional queries.