Representation lenses expose layer-wise predictions in LLMs. Current methods rely on full-rank affine maps with quadratic cost. How- ever, spectral evidence across multiple model families shows these maps are intrinsically low-rank. We propose LoRA-Lens, a low-rank residual alignment mechanism that reduces parameters by over 95% while preserv- ing fidelity to the model’s final output. Experiments on OLMo, Qwen, and Gemma (up to 32B) demonstrate strong fidelity, large memory sav- ings, robust transfer to instruction-tuned models, and effective early-exit inference.

Low-Rank Lens for Scalable LLMs Interpretability / Trimigno, G., Lombardo, G., Cagnoni, S.. - (2026).

Low-Rank Lens for Scalable LLMs Interpretability

Giuseppe Trimigno
Conceptualization
;
Gianfranco Lombardo
Methodology
;
Stefano Cagnoni
Supervision
2026-01-01

Abstract

Representation lenses expose layer-wise predictions in LLMs. Current methods rely on full-rank affine maps with quadratic cost. How- ever, spectral evidence across multiple model families shows these maps are intrinsically low-rank. We propose LoRA-Lens, a low-rank residual alignment mechanism that reduces parameters by over 95% while preserv- ing fidelity to the model’s final output. Experiments on OLMo, Qwen, and Gemma (up to 32B) demonstrate strong fidelity, large memory sav- ings, robust transfer to instruction-tuned models, and effective early-exit inference.
2026
Low-Rank Lens for Scalable LLMs Interpretability / Trimigno, G., Lombardo, G., Cagnoni, S.. - (2026).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11381/3059673
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