arXiv Machine Learning

Random Quadratic Form on a Sphere: Synchronization by Common Noise

arXiv:2603. 06187v2 Announce Type: replace-cross Abstract: We introduce the Random Quadratic Form (RQF): a stochastic differential equation which formally corresponds to the gradient flow of a random quadratic functional on a sphere.

arXiv Machine Learning
Oct 12

Asymptotic Analysis of Discrete-Time Self-Attention Dynamics in Transformers

The paper investigates the discrete-time self‑attention dynamics of transformers, providing a full classification of equilibria and their stability for both single‑head and multi‑head cases. It shows that the main attractor is a consensus equilibrium aligned with the principal eigenvector of the value matrix, while locally asymptotically stable bipartite equilibria also exist in the single‑head scenario. The theoretical findings are corroborated by examining learned weight matrices from an actual transformer.

By Claudio Altafini
arXiv Machine Learning
Jun 4

Drift-Diffusion Matching: Embedding dynamics in latent manifolds of asymmetric neural networks

arXiv:2602. 14885v2 Announce Type: replace-cross Abstract: Recurrent neural networks (RNNs) provide a theoretical framework for understanding computation in biological neural circuits, yet classical results, such as Hopfield's model of associative memory, rely on symmetric connectivity that restricts network dynamics to gradient-like flows.

By Ram\'on Nartallo-Kaluarachchi, Renaud Lambiotte, Alain Goriely
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
arXiv Machine Learning
Oct 22

Kinetic theory for Transformers and the lost-in-the-middle phenomenon

The paper investigates causal self‑attention dynamics in decoder Transformers, modeling them as a non‑exchangeable interacting particle system. Using cumulant expansions and Glauber calculus, the authors prove a quantitative mean‑field limit and a next‑order correlation characterization. For i.i.d. uniformly distributed tokens, they solve the limiting correlation equation in closed form and rigorously explain the empirically observed lost‑in‑the‑middle phenomenon, showing a U‑shaped token retrieval profile with primacy, recency, and a unique interior minimum under a smallness condition.

By Mitia Duerinckx, Borjan Geshkovski, Stefano Rossi