arXiv AI

Probability-Signature Dynamics: Unpacking Modular Addition Learning Within Two-Layer Networks

The paper investigates why neural networks trained on modular addition tasks develop Fourier-structured representations that enable exact generalization. Using probability signatures, the authors show that leading gradient interactions are cyclic shift operators, which are diagonalized by the discrete Fourier transform, leading to decoupled Fourier-mode dynamics that explain Fourier sparsity, frequency matching, and phase alignment. The framework also clarifies how label noise can accelerate early loss decrease by increasing conditional label collisions, and it is demonstrated to predict frequency behavior in other operators such as XOR.

arXiv Machine Learning
Oct 22

A Mechanistic Study of Algorithmic Generalization in Diffusion Models on Modular Arithmetic

The paper investigates how diffusion models learn and generalize algorithmically, focusing on a modular addition task with images. In a single‑image setting, the model encodes operands as periodic representations and combines them via self‑attention and feed‑forward layers that mirror trigonometric addition identities. In a diverse‑image setting, the sampling process separates into an arithmetic computation phase and a visual refinement phase, with the transition marked by an internal frequency‑entropy signal.

By Joon Hyeok Kim, Yong-Hyun Park, Mattis Dals{\ae}tra {\O}stby, Jiatao Gu
arXiv Machine Learning
Oct 8

Machine learning modularity

The paper introduces a transformer‑based sequence‑to‑sequence model with dynamic batching that automatically simplifies complex expressions involving multiple elliptic Gamma functions. It learns to apply algebraic identities, especially SL(2,ℤ) and SL(3,ℤ) modular transformations, to reduce scrambled expressions to canonical forms. Experiments show over 99% accuracy on in‑distribution tests and more than 90% accuracy under significant extrapolation, indicating the model internalizes the underlying algebraic rules rather than merely memorizing patterns.

By Yi Fan, Vishnu Jejjala, Yang Lei
arXiv Machine Learning
Oct 8

CAFE+FNO: Fourier Kernel Generation via Multiplicative Feature Composition

The paper introduces CAFE+FNO, a Fourier Neural Operator variant that enhances kernel generation by combining Fourier–Chebyshev features through parallel affine branches and a Hadamard product. This method produces frequency interactions explicitly, allowing a kernel MLP to map each normalized spectral coordinate to a complex channel‑mixing matrix while keeping the number of trainable parameters independent of the number of modes. Experiments on five PDE benchmarks and ablation studies demonstrate the effectiveness of the proposed basis configuration, multiplicative composition, and bandwidth learnability.

By Hyungjoon Juen, Minwoo Shin
Hugging Face Trending Papers
4d ago

Mode Dynamics: A Framework for Neural Network Learning

Mode Dynamics is a framework that links coordinated parameter motion during neural network training to changes in model outputs. By decomposing recorded parameter trajectories into collective modes and mapping each mode to its state‑dependent output effect, the framework uses decomposition, reconstruction, and concentration mechanisms to analyze how behavior emerges from parameter updates. Experiments on CIFAR‑100 autoencoding and a Pythia‑70M pretraining trajectory show that a small set of leading modes can reconstruct behavior, that induced effects depend on the training path, and that modal complexity varies with task and data.

arXiv Machine Learning
Aug 31

Euclidean Fourier Neural Operators

Euclidean Fourier Neural Operators (EFNOs) extend Fourier neural operators by making the spectral kernel a continuous function of physical wavevectors, thereby removing dependence on specific periodic domain shapes and sizes. This domain‑independent formulation allows EFNOs to learn operators that generalize across different grid resolutions and domain geometries. Experiments on a heat equation and a materials‑science task demonstrate that EFNOs can successfully transfer learned mappings to unseen grid sizes and crystal structures.

By Nathanael Bosch, Niklas Frederik Schmitz, Michael F. Herbst