arXiv Machine Learning

Phase Transitions in Attention: A Bayesian Theory of Copy Head Emergence

arXiv:2606. 12058v1 Announce Type: cross Abstract: Attention is the key mechanism underlying in-context learning in transformers, and attention patterns have been observed empirically to emerge abruptly during training.

arXiv Machine Learning
Jul 7

Incremental Learning of Sparse Attention Patterns in Transformers

arXiv:2602. 19143v2 Announce Type: replace Abstract: This paper studies simple transformers trained on a high-order Markov chain, where the model must incorporate information from multiple past positions, each with different statistical importance.

By O\u{g}uz Kaan Y\"uksel, Rodrigo Alvarez Lucendo, Nicolas Flammarion
arXiv Machine Learning
Jun 25

Emergent Capabilities Arise Randomly from Learning Sparse Attention Patterns

arXiv:2606. 25010v1 Announce Type: new Abstract: Neural scaling laws for transformer language models predict smooth improvements in pretraining loss with increasing parameters, but downstream capabilities such as in-context learning are known to emerge abruptly past a certain model scale.

By Vatsal Baherwani, Zixi Chen, Shikai Qiu, Andrew Gordon Wilson, Pavel Izmailov
arXiv Machine Learning
Jul 31

Critical attention scaling in long-context transformers

arXiv:2510. 05554v2 Announce Type: replace Abstract: As large language models scale to longer contexts, attention layers suffer from a fundamental pathology: attention scores collapse toward uniformity as context length $n$ increases, causing tokens to cluster excessively, a phenomenon known as rank-collapse.

By Shi Chen, Zhengjiang Lin, Yury Polyanskiy, Philippe Rigollet
arXiv Machine Learning
Jun 15

Beyond a Single Explanation of the Adam--SGD Gap

arXiv:2606. 14259v1 Announce Type: new Abstract: Prior work has identified several factors that can contribute to the performance gap between Adam and SGD, spanning data aspects, architecture design, and optimization properties.

By Chenxiang Zhang, Rustem Islamov, Enea Monzio Compagnoni, Jun Pang, Aurelien Lucchi, Antonio Orvieto
arXiv Machine Learning
Jul 7

Induction Heads Interpolate N-Grams

arXiv:2607. 02800v1 Announce Type: new Abstract: Induction heads are attention circuits believed to underlie in-context learning in transformers, yet a precise characterization of the estimators they implement remains elusive.

By Francesco D'Angelo, Oguz Kaan Yuksel, Swathi Shree Narashiman, Nicolas Flammarion