arXiv Statistics ML

Affine-invariant Cubic Newton with Weak Learners

arXiv Machine Learning
Oct 22

Curvature-Scaled Sharpness-Aware Minimization: Convergence Beyond Smoothness

The paper introduces Curvature-Scaled Sharpness-Aware Minimization (CS‑SAM), a variant of SAM that scales both the perturbation and descent step by curvature bounds to uniformly control gradient distortion under generalized smoothness conditions. It proves deterministic ≥1/T convergence rates for nonconvex objectives, last‑iterate ≥1/T rates for convex objectives, and linear convergence under the Polyak‑Łojasiewicz condition, while recovering standard gradient descent rates when the perturbation is zero. Experiments on computer vision tasks show that CS‑SAM, particularly the (H0,H1) variant, achieves the highest mean best‑test accuracy across four settings compared to tuned SAM and USAM.

By Dimitris Oikonomou, Nicolas Loizou
arXiv Machine Learning
Jun 30

Curvature-Weighted Gradient Diversity: A Noise Measure for Geometry-Adaptive SGD Schedules

arXiv:2606. 30455v1 Announce Type: new Abstract: The standard convergence analysis of mini-batch stochastic gradient descent (SGD) models gradient noise using a single variance term that treats all parameter directions equally, ignoring the fact that noise in high-curvature directions has less impact because learning rates are already constrained there.

By Muhammad Hamza (Indian Institute of Technology Kharagpur), Ayush Goel (Indian Institute of Technology Kharagpur)