arXiv Machine Learning

Revisiting the Objective of Echo Chamber Detection

The paper introduces a formal objective for detecting echo chambers in social networks, distinguishing it from community detection, graph cut, and clique problems. It employs Fourier transform theory of set functions to define the objective and proposes a scalable semidefinite relaxation solved with interior point methods and sparse linear algebra. Experiments on synthetic and real datasets show the algorithm outperforms existing methods in recovering ground‑truth echo chambers and producing better network properties, including higher agreement with suspended users.

arXiv Machine Learning
Jul 3

Provably Finding a Hidden Dense Submatrix among Many Planted Dense Submatrices via Convex Programming

arXiv:2601. 03946v3 Announce Type: replace-cross Abstract: We consider the densest submatrix problem, which seeks the submatrix of fixed size of a given binary matrix that contains the most nonzero entries.

By Valentine Olanubi (University of Alabama, Department of Mathematics), Phineas Agar (University of Alabama, Department of Mathematics), Brendan Ames (University of Southampton, School of Mathematical Sciences)
arXiv Machine Learning
Sep 10

Not Just Oversmoothing: Detecting the Echo Chamber Effect in Graph Neural Networks

The paper introduces the Echo Chamber Effect, a failure mode in Graph Neural Networks where intra-community representations collapse while inter-community separation remains, differing from traditional oversmoothing. It proposes the Echo Chamber Index (ECI) to detect this effect by stratifying pairwise distances by community membership. Building on this analysis, the authors present Community-Aware Split Propagation (CASP), a lightweight plugin that decouples intra- and inter-community aggregation and learns their balance from label structure, improving performance across various GNN backbones in both homophilic and heterophilic settings.

By Asela Hevapathige, Ahad N. Zehmakan, Asiri Wijesinghe, Saman Halgamuge
arXiv Machine Learning
Jun 18

Robust Detection of Planted Subgraphs in Semi-Random Models

arXiv:2508. 02158v2 Announce Type: replace-cross Abstract: Detection of planted subgraphs in Erd\"os-R\'enyi random graphs has been extensively studied, leading to a rich body of results characterizing both statistical and computational thresholds.

By Dor Elimelech, Wasim Huleihel
arXiv Machine Learning
Sep 17

Provable Guarantees for Spectral Structured Prediction

The paper presents provable guarantees for a spectral method that recovers binary node labels on signed graphs with edge‑flip noise. It provides graph‑structure‑agnostic bounds on approximate inference accuracy and maximum angle deviation, using matrix concentration and eigenvector perturbation techniques. The results connect to the Cheeger constant and are validated with synthetic experiments, marking the first theoretical analysis of this spectral approach.

By Violet Zheng, Jean Honorio
arXiv Machine Learning
1d ago

Degree-Corrected Joint Matrix Factorization for Multilayer Community Detection

The paper introduces a degree‑corrected joint matrix factorization technique for detecting communities in multilayer networks. It uses a nonnegative symmetric matrix trifactorization that enforces disjoint, shared communities across layers while allowing each layer to have distinct connectivity patterns and node degrees. An efficient algorithm is presented and evaluated on a multilayer degree‑corrected stochastic block model, showing superior performance compared to existing methods.

By Alexandra Dache, Manon Rustin, Arnaud Vandaele, Nicolas Gillis