activity
20242026
collaborators

7 papers

stat.ML2026

Phase Transition for Stochastic Block Model with more than Communities

Alexandra Carpentier, Christophe Giraud, Nicolas Verzelen

Predictions from statistical physics postulate that recovery of the communities in the Stochastic Block Model (SBM) with a fixed number of communities is possible in polynomial…

stat.ML2026

Low-degree lower bounds via almost orthonormal bases

Alexandra Carpentier, Simone Maria Giancola, Christophe Giraud +1

Low-degree polynomials have emerged as a powerful paradigm for providing evidence of statistical-computational gaps across a variety of high-dimensional statistical models [Wein25]…

math.ST2025

Minimax optimal seriation in polynomial time

Yann Issartel, Christophe Giraud, Nicolas Verzelen

We consider the seriation problem, whose goal is to recover a hidden ordering from a noisy observation of a permuted Robinson matrix. We establish sharp minimax rates under average…

stat.ML2025

Phase Transition for Stochastic Block Model with more than Communities (II)

Alexandra Carpentier, Christophe Giraud, Nicolas Verzelen

A fundamental theoretical question in network analysis is to determine under which conditions community recovery is possible in polynomial time in the Stochastic Block Model (SBM).…

math.ST2025

Computational barriers for permutation-based problems, and cumulants of weakly dependent random variables

Bertrand Even, Christophe Giraud, Nicolas Verzelen

In many high-dimensional problems,polynomial-time algorithms fall short of achieving the statistical limits attainable without computational constraints. A powerful approach to pro…

math.ST2025

Computational lower bounds in latent models: clustering, sparse-clustering, biclustering

Bertrand Even, Christophe Giraud, Nicolas Verzelen

In many high-dimensional problems, like sparse-PCA, planted clique, or clustering, the best known algorithms with polynomial time complexity fail to reach the statistical performan…