As Language Models Scale, Low-order Linear Depth Dynamics Emerge
- URL: http://arxiv.org/abs/2603.12541v1
- Date: Fri, 13 Mar 2026 00:51:53 GMT
- Title: As Language Models Scale, Low-order Linear Depth Dynamics Emerge
- Abstract summary: Large language models are often viewed as high-dimensional nonlinear systems and treated as black boxes.<n>We show that transformer depth dynamics admit accurate low-order linear surrogates within context.
- Score: 15.919212303210351
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Large language models are often viewed as high-dimensional nonlinear systems and treated as black boxes. Here, we show that transformer depth dynamics admit accurate low-order linear surrogates within context. Across tasks including toxicity, irony, hate speech and sentiment, a 32-dimensional linear surrogate reproduces the layerwise sensitivity profile of GPT-2-large with near-perfect agreement, capturing how the final output shifts under additive injections at each layer. We then uncover a surprising scaling principle: for a fixed-order linear surrogate, agreement with the full model improves monotonically with model size across the GPT-2 family. This linear surrogate also enables principled multi-layer interventions that require less energy than standard heuristic schedules when applied to the full model. Together, our results reveal that as language models scale, low-order linear depth dynamics emerge within contexts, offering a systems-theoretic foundation for analyzing and controlling them.
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