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arXiv · 2604.20313

Formalising the Logit Shift Induced by LoRA: A Technical Note

Xiang Shi·Shuaizhi Cheng·Mingwei Li
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Abstract

This technical note provides a first-order formalisation of the logit shift and fact-margin change induced by Low-Rank Adaptation (LoRA). Using a first-order Fr\'echet approximation around the base model trajectory, we show that the multi-layer LoRA effect can be decomposed into a linear summation of layerwise contributions and a higher-order remainder term representing inter-layer coupling.

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Xiang Shi, Shuaizhi Cheng, Mingwei Li. 2026-04-22. Formalising the Logit Shift Induced by LoRA: A Technical Note. https://arxiv.org/abs/2604.20313

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