MOSAIC: Minimax-Optimal Sparsity-Adaptive Inference for Change Points in Dynamic Networks

Fuente: arXiv
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Main Authors: Fan, Yingying, Liu, Jingyuan, Lv, Jinchi, Sun, Ao
Format: Preprint
Published: 2025
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author Fan, Yingying
Liu, Jingyuan
Lv, Jinchi
Sun, Ao
author_facet Fan, Yingying
Liu, Jingyuan
Lv, Jinchi
Sun, Ao
contents We propose a new inference framework, named MOSAIC, for change-point detection in dynamic networks with the simultaneous low-rank and sparse-change structure. We establish the minimax rate of detection boundary, which relies on the sparsity of changes. We then develop an eigen-decomposition-based test with screened signals that approaches the minimax rate in theory, with only a minor logarithmic loss. For practical implementation of MOSAIC, we adjust the theoretical test by a novel residual-based technique, resulting in a pivotal statistic that converges to a standard normal distribution via the martingale central limit theorem under the null hypothesis and achieves full power under the alternative hypothesis. We also analyze the minimax rate of testing boundary for dynamic networks without the low-rank structure, which almost aligns with the results in high-dimensional mean-vector change-point inference. We showcase the effectiveness of MOSAIC and verify our theoretical results with several simulation examples and a real data application.
format Preprint
id arxiv_https___arxiv_org_abs_2509_06303
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle MOSAIC: Minimax-Optimal Sparsity-Adaptive Inference for Change Points in Dynamic Networks
Fan, Yingying
Liu, Jingyuan
Lv, Jinchi
Sun, Ao
Machine Learning
Methodology
We propose a new inference framework, named MOSAIC, for change-point detection in dynamic networks with the simultaneous low-rank and sparse-change structure. We establish the minimax rate of detection boundary, which relies on the sparsity of changes. We then develop an eigen-decomposition-based test with screened signals that approaches the minimax rate in theory, with only a minor logarithmic loss. For practical implementation of MOSAIC, we adjust the theoretical test by a novel residual-based technique, resulting in a pivotal statistic that converges to a standard normal distribution via the martingale central limit theorem under the null hypothesis and achieves full power under the alternative hypothesis. We also analyze the minimax rate of testing boundary for dynamic networks without the low-rank structure, which almost aligns with the results in high-dimensional mean-vector change-point inference. We showcase the effectiveness of MOSAIC and verify our theoretical results with several simulation examples and a real data application.
title MOSAIC: Minimax-Optimal Sparsity-Adaptive Inference for Change Points in Dynamic Networks
topic Machine Learning
Methodology
url https://arxiv.org/abs/2509.06303