collaborators

8 papers

cs.LG2026

Fast Learning Rate Transfer in Shallow Linear Networks at Growing Training Horizons

Mana Sakai, Masaaki Imaizumi

Hyperparameter transfer across model width can substantially reduce the cost of tuning large neural networks, but its behavior when the training horizon grows with width is not ful…

cs.LG2026

Anti Mode-Collapse in Mean-Field Transformer via Auxiliary Variables

Masaaki Imaizumi, Masanori Koyama, Noboru Isobe +1

We use a mean-field-based transformer model to theoretically investigate how auxiliary variables, such as positional encoding, prevent mode collapse of self-attention mechanisms. T…

cs.LG2026

Training-Induced Escape from Token Clustering in a Mean-Field Formulation of Transformers

Noboru Isobe, Daisuke Inoue, Masaaki Imaizumi

Transformers perform inference by iteratively transforming token representations across layers. This layerwise computation has been studied empirically, and recent mean-field theor…

stat.ML2026

Spectrum-Adaptive Generalization Bounds for Trained Deep Transformers

Mana Sakai, Masaaki Imaizumi

Understanding why trained Transformers generalize well is a fundamental problem in modern machine learning theory, and complexity-based generalization bounds provide a principled w…

cs.CL2026

Why Mean Pooling Works: Quantifying Second-Order Collapse in Text Embeddings

Tomomasa Hara, Hiroto Kurita, Masaaki Imaizumi +2

For constructing text embeddings, mean pooling, which averages token embeddings, is the standard approach. This paper examines whether mean pooling actually works well in real mode…

stat.ML2026

High-Dimensional Limit of Stochastic Gradient Flow via Dynamical Mean-Field Theory

Sota Nishiyama, Masaaki Imaizumi

Modern machine learning models are typically trained via multi-pass stochastic gradient descent (SGD) with small batch sizes, and understanding their dynamics in high dimensions is…

cs.LG2026

Dichotomy of Feature Learning and Unlearning: Fast-Slow Analysis on Neural Networks with Stochastic Gradient Descent

Shota Imai, Sota Nishiyama, Masaaki Imaizumi

The dynamics of gradient-based training in neural networks often exhibit nontrivial structures; hence, understanding them remains a central challenge in theoretical machine learnin…

stat.ML2025

Precise Dynamics of Diagonal Linear Networks: A Unifying Analysis by Dynamical Mean-Field Theory

Sota Nishiyama, Masaaki Imaizumi

Diagonal linear networks (DLNs) are a tractable model that captures several nontrivial behaviors in neural network training, such as initialization-dependent solutions and incremen…