From Conditional to Unconditional Independence: Testing Conditional Independence via Transport Maps

Fuente: arXiv
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Autori principali: He, Chenxuan, Gao, Yuan, Zhu, Liping, Huang, Jian
Natura: Preprint
Pubblicazione: 2025
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author He, Chenxuan
Gao, Yuan
Zhu, Liping
Huang, Jian
author_facet He, Chenxuan
Gao, Yuan
Zhu, Liping
Huang, Jian
contents Testing conditional independence between two random vectors given a third is a fundamental and challenging problem in statistics, particularly in multivariate nonparametric settings due to the complexity of conditional structures. We propose a novel method for testing conditional independence by transforming it to an unconditional independence test problem. We achieve this by constructing two transport maps that transform conditional independence into unconditional independence, this substantially simplifies the problem. These transport maps are estimated from data using conditional continuous normalizing flow models. Within this framework, we derive a test statistic and prove its asymptotic validity under both the null and alternative hypotheses. A permutation-based procedure is employed to evaluate the significance of the test. We validate the proposed method through extensive simulations and real-data analysis. Our numerical studies demonstrate the practical effectiveness of the proposed method for conditional independence
format Preprint
id arxiv_https___arxiv_org_abs_2504_09567
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle From Conditional to Unconditional Independence: Testing Conditional Independence via Transport Maps
He, Chenxuan
Gao, Yuan
Zhu, Liping
Huang, Jian
Machine Learning
Methodology
62G05, 62G08, 68T07
Testing conditional independence between two random vectors given a third is a fundamental and challenging problem in statistics, particularly in multivariate nonparametric settings due to the complexity of conditional structures. We propose a novel method for testing conditional independence by transforming it to an unconditional independence test problem. We achieve this by constructing two transport maps that transform conditional independence into unconditional independence, this substantially simplifies the problem. These transport maps are estimated from data using conditional continuous normalizing flow models. Within this framework, we derive a test statistic and prove its asymptotic validity under both the null and alternative hypotheses. A permutation-based procedure is employed to evaluate the significance of the test. We validate the proposed method through extensive simulations and real-data analysis. Our numerical studies demonstrate the practical effectiveness of the proposed method for conditional independence
title From Conditional to Unconditional Independence: Testing Conditional Independence via Transport Maps
topic Machine Learning
Methodology
62G05, 62G08, 68T07
url https://arxiv.org/abs/2504.09567