arXiv AI
From Associations to Activations: Comparing Behavioral and Hidden-State Semantic Geometry in LLMs
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The information geometry of large language models is shared, learned, and controllable
The paper investigates how large language models (LLMs) share a common Fisher‑Rao geometry in their next‑token probability distributions, revealing that behaviour largely determines this geometry while activation geometry depends on coordinate choices. Across transformer, state‑space, and recurrent architectures, output geometries align more closely than activation geometries, and this shared structure facilitates semantic‑category transfer and improves agreement with human word choices as models scale and train. The study further demonstrates that geometry can guide minimum‑disturbance interventions, enabling reusable control that preserves behaviour better than Euclidean methods and enhances steering, editing, attribution, dictionary learning, and fine‑tuning.
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Meaning Contracts: Local Semantic Geometry in Large Language Models
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arXiv Machine Learning
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Comparing Latent Concept Formation in State Space Models and Transformers via Sparse Autoencoders
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