arXiv Machine Learning

AURA: Angular Update Rate Adaptation for training complex-valued neural networks

arXiv Machine Learning
Jul 27

Hyperball May Not Be a Free Lunch

arXiv:2607. 22444v1 Announce Type: new Abstract: For scale-invariant deep networks, Hyperball-style optimizers have shown strong performance in large-scale training by fixing the norms of matrix-valued parameters and normalizing updates.

By Yihao Xiao, Jialong Sun, Zitian Gao, Zeming Wei, Chutian Wang, Ran Tao, Jiaye Teng, Bryan Dai
arXiv Machine Learning
Jul 31

Towards Stability of Parameter-Free Optimization

arXiv:2405. 04376v4 Announce Type: replace Abstract: Hyperparameter tuning, particularly the selection of an appropriate learning rate in adaptive gradient training methods, remains a challenge.

By Yijiang Pang, Shuyang Yu, Bao Hoang, Jiayu Zhou
arXiv Machine Learning
Aug 4

AOS: Adaptive Optimizer Switching via Training-State Signals for Faster Convergence and Better Generalization

arXiv:2608. 01997v1 Announce Type: new Abstract: Single-optimizer training is a poor fit for the distinct phases of deep network optimization: adaptive methods handle noisy early gradients well but overshoot flat minima, while SGD with momentum generalizes better in the late phase but converges slowly early on.

By Alok Kumar Pandey, Umang Chaturvedi, Aatish Rana, Gopi Krishna Nedanuri
arXiv Machine Learning
1d ago

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
Sep 24

The Drift Contract: Spectral Updates for Depth-Robust Local Learning

The paper introduces the Drift Contract, a spectral update geometry for local learning that improves depth robustness and hyperparameter stability. By applying momentum orthogonalization with spectral step scaling to per‑layer updates, the authors achieve consistent performance across a wide range of widths and depths on CIFAR‑10 MLPs, outperforming local Adam and providing a per‑layer, input‑conditioned drift bound. The study also shows that the spectral geometry itself, rather than step‑size rules, drives the observed depth robustness, while a negative result indicates that the stability benefit is limited to non‑normalized layers.

By Fabien Polly
arXiv Machine Learning
Aug 31

Blog: Survey of Optimizers

The article surveys recent neural‑network optimizers, noting that the field has moved beyond simple Adam variants to encompass matrix‑ and layer‑level designs, time‑policy horizons, and state representations that survive sharding and low‑precision computation. It categorizes optimizers along four axes—temporal estimation, update geometry, horizon management, and representation & systems—highlighting methods such as Muon, Shampoo, SOAP, and quantized states. The survey concludes that while matrix‑aware methods are a genuine advance, no single optimizer universally replaces AdamW, and performance depends on model scale, data‑to‑parameter ratio, batch size, schedule, partitioning, tuning budget, and target metric.

By Ruoran Xu
arXiv Machine Learning
Sep 11

ExpTest: Loss-Curve Hypothesis Testing for Autonomous Learning-Rate Selection in Deep Neural Networks

ExpTest is an autonomous learning‑rate controller that uses the training loss curve as an online signal to perform sequential statistical tests on theoretically motivated windows, detecting convergent behavior and triggering learning‑rate reductions. It combines a covariance‑based initial learning‑rate estimate, curvature‑motivated window sizing, and a two‑phase test‑driven decay, relying on the approximately exponential decay predicted under linearized network dynamics. Experiments on regression, classification, forecasting, and natural‑language tasks across various architectures show that ExpTest achieves competitive performance compared to hand‑tuned SGD baselines and recent learning‑rate‑free methods, without requiring manual initial learning‑rate selection or predefined scheduling.

By Zan Chaudhry, Naoko Mizuno
arXiv Machine Learning
Jun 9

Convergence Bound and Critical Batch Size of Muon Optimizer

arXiv:2507. 01598v5 Announce Type: replace Abstract: Muon, a recently proposed optimizer that leverages the inherent matrix structure of neural network parameters, has demonstrated strong empirical performance, indicating its potential as a successor to standard optimizers such as AdamW.

By Naoki Sato, Hiroki Naganuma, Hideaki Iiduka