Achieving the Kesten-Stigum bound in the non-uniform hypergraph stochastic block model
Summary
This research investigates community detection in the non-uniform hypergraph stochastic block model (HSBM), which incorporates hyperedges of varying sizes to capture higher-order interactions. The study establishes a Kesten–Stigum-type bound for weak recovery in general non-uniform HSBMs with $r$ blocks. For the $r=2$ case, it demonstrates that weak recovery is achievable if the sum of signal-to-noise ratios across all uniform hypergraph layers exceeds one, confirming a conjecture from [CEH23]. The authors propose a polynomial-time spectral algorithm that leverages an optimally weighted non-backtracking operator to reach this threshold. The approach develops a spectral theory for weighted non-backtracking operators on non-uniform hypergraphs, including a precise characterization of outlier eigenvalues and eigenvector overlaps, and introduces a novel Ihara–Bass formula for efficient low-dimensional representation.
Key takeaway
For AI Scientists and Research Scientists working on community detection in complex, multi-modal datasets, this work provides a principled method to achieve optimal weak recovery. By applying the proposed optimally weighted non-backtracking spectral algorithm, you can combine signals from multiple hypergraph layers, even if individual layers are below their detection thresholds. This approach offers a computationally efficient way to cluster non-uniform hypergraphs and resolve previous conjectures on detection limits.
Key insights
Combining subcritical hypergraph layers can enable weak recovery if their aggregate signal-to-noise ratio surpasses a Kesten–Stigum-type bound.
Principles
- Optimal weighting aggregates heterogeneous higher-order interactions.
- Non-backtracking operators enable spectral theory for non-uniform hypergraphs.
Method
A polynomial-time spectral algorithm using an optimally weighted non-backtracking operator achieves the Kesten–Stigum bound for weak recovery in non-uniform HSBMs.
In practice
- Use optimal hyperedge reweighting for improved spectral clustering.
- Apply the Ihara–Bass formula for efficient reduced operator computation.
Topics
- Non-uniform Hypergraph SBM
- Community Detection
- Kesten-Stigum Bound
- Spectral Algorithms
- Weighted Non-backtracking Operator
Best for: AI Scientist, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by stat.ML updates on arXiv.org.