arXiv Machine Learning

Slow Beats Fast at the Kesten-Stigum Threshold: Minimax, Fisher-Information and Belief-Propagation Characterizations of the Information-Computation Gap in Sparse Stochastic Block Models

arXiv:2610. 08872v1 Announce Type: cross Abstract: We study community recovery in the sparse symmetric stochastic block model with $q$ communities, average degree $d$ and signal strength $\lambda$ through statistical decision theory and Fisher information, and obtain three characterizations of the Kesten-Stigum threshold $d\lambda^2=1$ and of the information-computation gap below it.

arXiv Statistics ML
1d ago

Community detection with the Bethe-Hessian

arXiv:2411.02835v3 Announce Type: replace-cross Abstract: The Bethe-Hessian matrix, introduced by Saade, Krzakala, and Zdeborov\'a (2014), is a Hermitian matrix designed for applying spectral cluster...

By Ludovic Stephan, Yizhe Zhu
arXiv Statistics ML
4d ago

Bethe Hessian Recovery through the Kesten-Stigum Regime

arXiv:2610. 41802v1 Announce Type: cross Abstract: We show that outlier eigenvectors of the Bethe Hessian achieve weak recovery in the stochastic block model down to the Kesten-Stigum threshold, for every fixed common expected degree $d>1$.

By Dingding Dong, Theo McKenzie
arXiv Statistics ML
4d ago

On Statistical-Computational Gaps in Graph Combinatorial Testing Problems

The paper investigates high‑dimensional graph combinatorial hypothesis testing where a signal resides on the edges of an unknown subgraph. For Gaussian observations, it derives sharp statistical and computational thresholds for detecting the signal across various graph alternatives, using second‑moment bounds of likelihood ratios and low‑degree methods. The authors also establish a transfer principle linking exponential family models, identify new statistical‑computational gaps for structures like multiple planted cliques and hypercliques, and provide matching upper bounds under local regularity, thereby revealing universal threshold scales and connecting Gaussian and Erdős–Rényi settings.

By Ikjun Choi, Pratik Patil, Alessandro Rinaldo