Fundamental Limits of Spectral Clustering in Stochastic Block Models

Fuente: arXiv
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Main Author: Zhang, Anderson Ye
Format: Preprint
Published: 2023
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author Zhang, Anderson Ye
author_facet Zhang, Anderson Ye
contents Spectral clustering has been widely used for community detection in network sciences. While its empirical successes are well-documented, a clear theoretical understanding, particularly for sparse networks where degrees are much smaller than $\log n$, remains unclear. In this paper, we address this significant gap by demonstrating that spectral clustering offers exponentially small error rates when applied to sparse networks under Stochastic Block Models. Our analysis provides sharp characterizations of its performance, backed by matching upper and lower bounds possessing an identical exponent with the same leading constant. The key to our results is a novel truncated $\ell_2$ perturbation analysis for eigenvectors, coupled with a new analysis idea of eigenvectors truncation.
format Preprint
id arxiv_https___arxiv_org_abs_2301_09289
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Fundamental Limits of Spectral Clustering in Stochastic Block Models
Zhang, Anderson Ye
Statistics Theory
Social and Information Networks
Spectral Theory
Spectral clustering has been widely used for community detection in network sciences. While its empirical successes are well-documented, a clear theoretical understanding, particularly for sparse networks where degrees are much smaller than $\log n$, remains unclear. In this paper, we address this significant gap by demonstrating that spectral clustering offers exponentially small error rates when applied to sparse networks under Stochastic Block Models. Our analysis provides sharp characterizations of its performance, backed by matching upper and lower bounds possessing an identical exponent with the same leading constant. The key to our results is a novel truncated $\ell_2$ perturbation analysis for eigenvectors, coupled with a new analysis idea of eigenvectors truncation.
title Fundamental Limits of Spectral Clustering in Stochastic Block Models
topic Statistics Theory
Social and Information Networks
Spectral Theory
url https://arxiv.org/abs/2301.09289