arXiv Machine Learning

Limit Theorems for Stochastic Gradient Descent in High-Dimensional Single-Layer Networks

arXiv:2511. 02258v3 Announce Type: replace-cross Abstract: This paper studies the high-dimensional scaling limits of online stochastic gradient descent (SGD).

arXiv AI
Sep 3

Percolation Dynamics in Optimization : Variance Cascades and Discrete Scale Invariance

The paper models the dynamics of Stochastic Gradient Descent (SGD) as a percolation process, showing that architectural symmetries cause subnetworks to merge in discrete blocks rather than sequentially. These structural transitions produce variance spikes in a macroscopic order parameter, analogous to physical phase transitions. The authors also demonstrate that this trapping mechanism and its scaling cascade apply to Adam and AdamW under a heavy‑tailed noise model.

By Sai Niranjan Ramachandran, Suvrit Sra
arXiv AI
3d ago

Mean--Fluctuation Dynamics at the Edge of Stability

The paper investigates gradient descent dynamics in the Edge of Stability regime, where a large learning rate causes persistent oscillations linked to improved generalization. It introduces a tractable continuous‑time mean–fluctuation model that couples the window‑averaged trajectory with its fluctuation covariance, derives this model rigorously from a sharp‑valley framework, and analyzes its stationary states and linear stability. The authors also extend the model to wide two‑layer networks, deriving a Wasserstein‑2 gradient flow for weights and fluctuations, proving well‑posedness, a mean‑field limit, and conditional convergence results, with numerical experiments illustrating the predictions and finite‑time limitations.

By Antonin Chodron de Courcel
Hugging Face Trending Papers
Jul 5

Broken Ergodicity and the Violation of the Fluctuation-Dissipation Theorem Lead to Generalization Beyond Overfitting in Machine Learning

The remarkable ability of modern neural networks to generalize improves with increasing network capacity, even when the number of model parameters or effective degrees of freedom exceeds the number of training data points. This phenomenon is all the more surprising given that generalization error diverges when the number of model parameters approaches a critical value from below.

arXiv Machine Learning
Sep 4

Correlated initialization of deep residual networks

The paper investigates how deep residual networks behave when their initial weights are correlated across layers. It confirms a conjecture that such correlated initializations interpolate between a Brownian stochastic differential equation (for independent weights) and an ordinary differential equation (for perfectly correlated weights). By applying a feature function to a stationary Gaussian sequence with regularly varying correlation, the authors prove that a unique critical scaling exists, leading the infinite‑depth limit to a Young differential equation driven by a Hermite process, which reduces to fractional Brownian motion when the feature function has Hermite rank one. The study shows that the correlation structure and Hermite rank of the initialization uniquely determine the critical scaling and asymptotic limit, making them meaningful hyperparameters in the asymptotic regime, whereas finite‑variance i.i.d. initialization always yields a Brownian driver regardless of distribution.

By Felix Benning, Ivan Nourdin, Giovanni Peccati