Eigenvalue Calibration for Semantic Embeddings of Large Language Models

This could be an interesting new paper by Francis Bach and his team! Perhaps, it is a more narrowly focused technical paper.

From the abstract:

"Uncertainty quantification is central to the reliable deployment of large language models (LLMs), and eigenvalues of semantic embeddings have recently emerged as a key tool in state-of-the-art methods. However, conventional calibration results developed for classification probabilities cannot be directly transferred to eigenvalues.

We address this gap by proposing a novel framework for calibrating the eigenvalues of semantic embeddings. We interpret LLMs combined with semantic embeddings of their generated answers as density matrix predictors, and we propose a novel approach to calibrate density matrix predictors by applying temperature scaling to their eigenvalues.

We establish entropy-risk equivalence under calibration, derive a central calibration inequality specific to eigenvalues, and prove that temperature-scaled eigenvalues optimize calibration when minimizing proper score risks.

Experiments on a variety of real-world settings show that current LLMs are systematically overconfident, and validate our theoretical findings.

Together, these results advance the foundations and practice of uncertainty quantification for semantic embeddings."

[2607.08377] Eigenvalue Calibration for Semantic Embeddings of Large Language Models (preprint, open access)