The Asymptotic Behavior of Attention in Transformers

Fuente: arXiv
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Auteurs principaux: Abella, Álvaro Rodríguez, Silvestre, João Pedro, Tabuada, Paulo
Format: Preprint
Publié: 2024
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author Abella, Álvaro Rodríguez
Silvestre, João Pedro
Tabuada, Paulo
author_facet Abella, Álvaro Rodríguez
Silvestre, João Pedro
Tabuada, Paulo
contents The transformer architecture has become the foundation of modern Large Language Models (LLMs), yet its theoretical properties are still not well understood. As with classic neural networks, a common approach to improve these models is to increase their size and depth. However, such strategies may be suboptimal, as several works have shown that adding more layers yields increasingly diminishing returns. More importantly, prior studies have shown that increasing depth may lead to model collapse, i.e., all the tokens converge to a single cluster, undermining the ability of LLMs to generate diverse outputs. Building on differential equation models for the transformer dynamics, we prove that all the tokens in a transformer asymptotically converge to a cluster as depth increases. At the technical level we leverage tools from control theory, including consensus dynamics on manifolds and input-to-state stability (ISS). We then extend our analysis to autoregressive models, exploiting their structure to further generalize the theoretical guarantees.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02682
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The Asymptotic Behavior of Attention in Transformers
Abella, Álvaro Rodríguez
Silvestre, João Pedro
Tabuada, Paulo
Artificial Intelligence
Machine Learning
Systems and Control
Dynamical Systems
Optimization and Control
The transformer architecture has become the foundation of modern Large Language Models (LLMs), yet its theoretical properties are still not well understood. As with classic neural networks, a common approach to improve these models is to increase their size and depth. However, such strategies may be suboptimal, as several works have shown that adding more layers yields increasingly diminishing returns. More importantly, prior studies have shown that increasing depth may lead to model collapse, i.e., all the tokens converge to a single cluster, undermining the ability of LLMs to generate diverse outputs. Building on differential equation models for the transformer dynamics, we prove that all the tokens in a transformer asymptotically converge to a cluster as depth increases. At the technical level we leverage tools from control theory, including consensus dynamics on manifolds and input-to-state stability (ISS). We then extend our analysis to autoregressive models, exploiting their structure to further generalize the theoretical guarantees.
title The Asymptotic Behavior of Attention in Transformers
topic Artificial Intelligence
Machine Learning
Systems and Control
Dynamical Systems
Optimization and Control
url https://arxiv.org/abs/2412.02682