arXiv Machine Learning

Fast Rates for Nonstationary Weighted Risk Minimization

The paper investigates weighted empirical risk minimization under nonstationary data, decomposing the excess risk into a learning component and a drift component. It establishes oracle inequalities for the learning error under mixing conditions, uniformly over arbitrary weight classes, and derives explicit bounds for drift errors in square loss settings, covering structural‑break and smoothly drifting processes. The analysis is extended to auto‑regression problems with linear models, basis approximations, and neural networks, revealing that optimal weights balance learning and drift via a bias–variance trade‑off and recover minimax‑optimal rates in unweighted, stationary cases.

arXiv Statistics ML
Oct 12

Beyond Discrepancy: Oracle Drift in Nonstationary Weighted Risk Minimization

The paper studies distributional drift in nonstationary weighted risk minimization by breaking down excess risk into estimation, drift, and approximation parts. It argues that traditional discrepancy-based bounds are often overly conservative because they can scale larger than the actual excess-risk contribution and react to risk surface changes that do not affect the optimal predictor. The authors provide a tighter oracle drift bound, analyze its behavior in parametrized regression models—particularly linear regression—and extend the results to nonparametric regression.

By Tobias Brock, Thomas Nagler
arXiv Machine Learning
Sep 11

General Quantification of Covariate and Concept Shifts

arXiv:2609. 11918v1 Announce Type: new Abstract: Generalization under distribution shift remains a core challenge in modern machine learning, yet existing learning bound theory is limited to narrow, idealized settings and is non-estimable from samples.

By Hongbo Chen, Li Charlie Xia
arXiv Machine Learning
Jun 8

Covariance Shrinkage via Stochastic Interpolation

arXiv:2606. 07382v1 Announce Type: new Abstract: We recast classical shrinkage of high-dimensional covariance estimators as empirical risk minimization over a parametric stochastic interpolant between a source and a target distribution.

By Mathieu Chalvidal, Florentin Coeurdoux, Eric Vanden-Eijnden
arXiv Machine Learning
Aug 26

A Data-dependent Early Stopping Rule using Rademacher Complexity with L1-norm

The paper proposes an analytic method for determining the optimal early‑stopping time in training neural networks, avoiding the need for gradient‑descent training. It uses Rademacher complexity with an L1‑norm to estimate generalization error, offering a more general approach than previous random‑matrix‑theory based methods. The framework is demonstrated on linear regression and extended to nonlinear neural networks via linear probing, as shown in a MNIST classification example.

By Duy Hoang, Bastien Berret, Olivier Bruneau, Laurent Fribourg
arXiv Statistics ML
Sep 14

A data-driven Fourier-mixture neural-network method for density estimation

The paper introduces a data‑driven Fourier‑trained neural‑network estimator for fixed‑horizon probability densities, using a positive Gaussian–Laplace mixture with a closed‑form characteristic function. Training occurs directly in Fourier space, enabling non‑negativity and unit‑mass preservation while handling both i.i.d. and resampling‑based pseudo‑sampling data. The authors provide theoretical error bounds, a multidimensional extension, and demonstrate competitive empirical performance against Expectation–Maximization, especially on heavy‑tailed targets.

By Duy-Minh Dang, Volter Entoma