arXiv Machine Learning

RobustLDS: Learning linear dynamical systems under adversarial corruptions

arXiv:2610. 11906v1 Announce Type: cross Abstract: We consider the problem of learning linear dynamical systems under adversarial contamination from a single trajectory of length $T$.

arXiv Machine Learning
Sep 3

Median-of-Means as an Extremal Convex Estimator and a Nonconvex Route to the Trimmed Oracle

The paper revisits median‑of‑means estimation from a deterministic optimization perspective, introducing a family of block‑Lp estimators (for 0 < p ≤ 1) that achieve robust learning with heavy‑tailed and adversarially corrupted data. It shows that any convex block M‑estimator cannot attain the trimmed‑block oracle constant, while the nonconvex block‑Lp family provides finite‑sample robustness bounds that approach this oracle constant as p decreases. The authors also prove that the block‑Lp objectives have a benign landscape—every local minimum is close to the true parameter—and combine these results with block‑level concentration to obtain sub‑Gaussian deviation bounds under finite 2+δ moments, extending to high‑dimensional robust mean estimation and sparse regression.

By Angshul Majumdar
arXiv AI
Sep 18

Exploring Sparsity and Smoothness of Arbitrary Lp Norms in Adversarial Attacks

The paper investigates how the choice of the π parameter in λπ norm-constrained adversarial attacks influences the sparsity and smoothness of the perturbations. By applying two established sparsity metrics and introducing three new smoothness measures—including one based on first-order Taylor approximations—the authors perform extensive experiments on real-world image datasets and various neural network architectures. Their results indicate that λρ norms with π values between 1.3 and 1.5 consistently provide the best balance between sparsity and smoothness, challenging the common use of λ1 or λ2 norms.

By Christof Duhme, Florian Eilers, Xiaoyi Jiang
arXiv Machine Learning
Sep 23

On the Gradient Heterogeneity Dynamics of Adversarially Robust Federated Regression

The paper studies federated learning where honest clients have heterogeneous data-generating models and adversarial clients can exacerbate this heterogeneity by sending arbitrary updates. It derives new bounds on gradient heterogeneity for linear and nonlinear regression, separating effects from honest clients’ model differences, label noise, and initialization. The authors show that for any (f,κ)-robust aggregator with κ = O(f/n) (where f is the number of adversarial clients and n the total number of clients, with f/n < 1/2), convergence is guaranteed after an explicit sample burn‑in period.

By Leonardo F. Toso, James Anderson, Nirupam Gupta, Rafael Pinot
arXiv Machine Learning
Jul 15

Linear Regression under Missing or Corrupted Coordinates

arXiv:2509. 19242v2 Announce Type: replace-cross Abstract: We study multivariate linear regression under Gaussian covariates in two settings, where data may be erased or corrupted by an adversary under a coordinate-wise budget.

By Ilias Diakonikolas, Jelena Diakonikolas, Daniel M. Kane, Jasper C. H. Lee, Thanasis Pittas
arXiv Machine Learning
Jul 7

Adversarial LassoNet: Robust Feature Selection via Stability-Driven Sparse Learning

arXiv:2607. 03839v1 Announce Type: new Abstract: Sparse feature selection is critical for high-dimensional machine learning, yet traditional $\ell_1$-regularized methods are often brittle under observational noise and spurious correlations, leading to unstable feature supports and degraded generalization.

By Zhen Huang, Peicheng Xu, Junbiao Pang, Yulong Zheng