arXiv Machine Learning
5d ago

Understanding Practical Optimization in Machine Learning

The thesis investigates practical optimization techniques used in modern machine learning, such as submodel training, gradient clipping, and layer-wise non‑Euclidean directions, by analyzing their actual objectives, assumptions, updates, and computations rather than simplified proxies. It demonstrates that Independent Subnetwork Training can converge to a shifted fixed point due to sketching bias, while Model‑Agnostic Sparsified Training incorporates the sketch distribution to achieve unbiased gradients and convergence guarantees. The work also explores private optimization, showing that adaptive quantile clipping retains bias unless a suitable schedule is used, and combines smoothed normalization with error compensation to obtain distributed private convergence without bounded gradient assumptions. Additionally, it develops a layer‑wise generalized smoothness model for optimizers based on linear minimization oracles, validates it through the Gluon framework, and highlights the importance of precise orthogonalization in Muon‑style methods.

By Egor Shulgin
arXiv Machine Learning
Oct 19

Towards Hyperparameter Transfer for Differentially Private Optimization

The paper introduces DP‑µP, a framework that extends Maximal Update Parametrization to differential privacy settings. By analyzing gradient clipping, noise injection, and feature learning, it derives a signal‑to‑noise ratio condition and spectral scaling rules for DP‑SGD, DP‑Adam, and DP‑Muon optimizers. Experiments show that DP‑µP enables zero‑shot transfer of learning rates across model widths on MLP, ViT, and GPT‑2, matching or surpassing tuned baselines while cutting computational costs.

By Tianze Wang, Zhiqi Bu, Linjun Zhang