arXiv AI

Correcting Before Adapting: Gradient Correction for Federated Adaptive Optimization

The paper introduces Federated Adaptive Gradient Correction (FA‑GC), a method that corrects each gradient before it is incorporated into the running averages used by adaptive optimizers like Adam in federated learning. Compared to a naive correction approach (FA‑NT) that only adjusts the final update direction, FA‑GC ensures that the corrected direction only vanishes at global stationary points and provides convergence guarantees without client‑heterogeneity terms. Experiments on seven image and language tasks show that FA‑GC with Adam achieves target accuracy in fewer rounds and, in some cases, reduces total communication compared to uncorrected local Adam and FA‑NT.

arXiv Machine Learning
Jun 3

MAdam: Metric-Aware Multi-Objective Adam

arXiv:2606. 03904v1 Announce Type: new Abstract: Multi-objective optimization (MOO) underlies many machine learning problems, yet MOO solvers across the loss-balancing, gradient-balancing, and Pareto-based families almost universally hand their reconciled directions to Adam~\cite{kingma2015adam}.

By Fengbei Liu, Rachit Saluja, Sunwoo Kwak, Ruibo Wang, Ruining Deng, Heejong Kim, Johannes C. Paetzold, Mert R. Sabuncu
arXiv Machine Learning
Aug 27

How Edge of Stability Hinders SCAFFOLD in Federated Optimization

The paper investigates why the SCAFFOLD algorithm, designed to be robust to data heterogeneity in federated learning, often underperforms compared to the simpler FedAvg. It identifies the presence of Edge of Stability (EoS) dynamics and progressive sharpening as key factors, showing that both algorithms exhibit EoS behavior across various architectures and hyperparameters. Crucially, the study finds that at the EoS, SCAFFOLD’s ability to estimate the global gradient deteriorates, as indicated by a weakened correlation between sharpness and gradient estimation error, explaining its limited practical advantage.

By Anant Khandelwal, Michael Crawshaw, Mingrui Liu
arXiv Machine Learning
Jul 7

Learning rate adaptive stochastic gradient descent optimization methods: numerical simulations for deep learning methods for partial differential equations and convergence analyses

arXiv:2406. 14340v2 Announce Type: replace-cross Abstract: The standard stochastic gradient descent (SGD) optimization method, as well as adaptive methods such as the Adam optimizer fail to converge if the learning rates do not converge to zero (particularly, in the situation of constant learning rates).

By Steffen Dereich, Arnulf Jentzen, Adrian Riekert