Math: Robust statistics

Machine-learning ideas tagged Robust statistics in the Math taxonomy of the Math2NN corpus.

✗ Mechanism failed 2026

Spectral-filtered task-gradient optimizer

Replace the ordinary average of task or client gradients with an iterative spectral filter that removes tasks whose gradient vectors explain an anomalously large covariance direction. The global model uses the filtered gradient, while each task still maintains its own personalized parameters and local optimizer state. Unlike parameter-center regularization, the robustification acts directly on the vector messages and is designed to avoid an additional \(\sqrt d\) contamination penalty.

Useful8/10
Difficulty5/10
Novelty5/10
Paper: Contaminated Multi-task Learning with Heterogeneity: Fundamental Limits and Optimal Algorithms arXiv:2607.02681
Unverified 2026

Quantile-space Huber-Wasserstein loss

For models that predict probability distributions, replace the usual Wasserstein-2 loss or a Huber penalty on the final Wasserstein distance with a Huber penalty on quantile-by-quantile prediction errors. This suppresses gradients from localized outliers while retaining quadratic gradients on the majority of the distribution, which is useful for uncertainty prediction, histogram prediction, and distributional distillation.

Useful6/10
Difficulty3/10
Novelty5/10
Paper: Huber-Wasserstein barycenters for robust distribution-valued data arXiv:2608.13131