arXiv Machine Learning

Blockwise Stabilized Adaptive Cubic Regularization with Subsolvers via Recurrence

arXiv Statistics ML
6d ago

Affine-invariant Cubic Newton with Weak Learners

arXiv:2610.33516v1 Announce Type: new Abstract: Modern gradient boosting algorithms are based on Newton's method, which excels empirically but lacks global convergence guarantees. While recent work o...

By Nikita Zozoulenko, Daniel Falkowski, Thomas Cass, Lukas Gonon
arXiv Machine Learning
5d ago

Accelerating LLM Pre-Training through Flat-Direction Dynamics Enhancement

The paper introduces LITE, a strategy that accelerates large language model pre‑training by enhancing dynamics along flat directions in the optimization landscape. It builds on a Riemannian ODE framework to interpret adaptive optimizers, then applies larger Hessian damping coefficients and learning rates to improve convergence. Experiments show LITE speeds up Muon and SOAP across various architectures, scales, datasets, and learning‑rate schedules.

By Shuchen Zhu, Rizhen Hu, Mingze Wang, Mou Sun, Xue Wang, Kun Yuan, Zaiwen Wen
arXiv Machine Learning
Oct 12

Second-Order Optimization with Asynchronous Curvature

The paper introduces Split-Client, a task‑parallel scheme that separates Hessian factorization (performed by a curvature client in the background) from gradient updates (performed by a gradient client using the latest available Hessian). It proves that the resulting first‑order stationarity bound depends on the average age of the curvature matrix rather than its maximum, and extends this analysis to subsampled and inexact Hessians. Experiments on two LIBSVM datasets show that this approach reduces the objective faster in wall‑clock time than both Lazy and Vanilla cubic Newton, especially at intermediate accuracy levels.

By El Mahdi Chayti, Martin Jaggi
arXiv Machine Learning
Aug 27

Adaptive Hybrid Subspace Levenberg Marquardt Algorithm with Adequacy Monitor for Large Scale Least Squares Problems

The paper introduces an Adaptive Hybrid Subspace Levenberg–Marquardt (HSLM) algorithm that tackles large‑scale nonlinear least‑squares problems by building a low‑dimensional subspace from gradient, memory, Krylov‑subspace, and randomized curvature data. It employs a deterministic adequacy monitor to adaptively enrich the subspace and decouples step acceptance from damping adjustment, using Armijo backtracking for step length and a ratio of actual to predicted reduction for damping updates. The authors prove global convergence to stationarity and local linear and superlinear convergence, and demonstrate that HSLM matches the convergence of classical and Krylov‑subspace LM while significantly reducing per‑iteration cost, especially as the parameter dimension increases.

By M. Duc Hoang, Timothy J. Lewis
arXiv Machine Learning
Oct 3

Trust the Direction, Search the Step: Zero-and-First-Order Methods for LLM Fine-Tuning

The paper introduces ZFO, a lightweight framework that separates direction selection from step-size determination in large‑scale neural network optimization. ZFO uses a trusted first‑order optimizer to pick a search direction and then performs only two additional objective evaluations to build a local curvature‑aware model, selecting an adaptive step within a bounded interval. The authors provide theoretical guarantees for reliable curvature estimation, near‑optimal step selection, and convergence to a stationary point, and demonstrate that ZFO improves optimization and final performance over fixed‑step first‑order baselines on language‑model fine‑tuning tasks.

By Cristian McGee, El Houcine Bergou, Aritra Dutta
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