Hallucination Detection: A Probabilistic Framework Using Embeddings Distance Analysis
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Abstract (arXiv)
Hallucinations are one of the major issues affecting LLMs, hindering their wide adoption in production systems. While current research solutions for detecting hallucinations are mainly based on heuristics, in this paper we introduce a mathematically sound methodology to reason about hallucination, and leverage it to build a tool to detect hallucinations. To the best of our knowledge, we are the first to show that hallucinated content has structural differences with respect to correct content. To prove this result, we resort to the Minkowski distances in the embedding space. Our findings demonstrate statistically significant differences in the embedding distance distributions, that are also scale free -- they qualitatively hold regardless of the distance norm used and the number of keywords, questions, or responses. We leverage these structural differences to develop a tool to detect hallucinated responses, achieving an accuracy of 66% for a specific configuration of system parameters -- comparable with the best results in the field. In conclusion, the suggested methodology is promising and novel, possibly paving the way for further research in the domain, also along the directions highlighted in our future work.
Key facts. Cited by 5 papers in the map (data through 7 Oct 2026). Builds on 33 of its 49 references that are in the map. First posted on arXiv 10 Feb 2025.
Builds on
33 of 49 references.
References · 33
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21 more
- 2024INSIDE: LLMs' Internal States Retain the Power of Hallucination Detectioncited by 317
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Built on by
Citing papers per year: 2025: 3; 2026: 2.
5 papers.
- 2025Embedding Trust: Semantic Isotropy Predicts Nonfactuality in Long-Form Text Generationcited by 1
- 2025PRISM: Phase-enhanced Radial-based Image Signature Mapping framework for fingerprinting AI-generated imagescited by 0
- 2025The Semantic Illusion: Certified Limits of Embedding-Based Hallucination Detection in RAG Systemscited by 0
- 2026Text Corpora as Concept Fields: Black-Box Hallucination and Novelty Measurementcited by 0
- 2026ASK-NN: An Asymmetric Nearest-Neighbor Test that detects Distribution Drifts in Natural Languagecited by 0
- 2026ASK-NN: An Asymmetric Nearest-Neighbor Test that detects Distribution Drifts in Natural Language17 Jul 2026
- 2026Text Corpora as Concept Fields: Black-Box Hallucination and Novelty Measurement6 May 2026
- 2025The Semantic Illusion: Certified Limits of Embedding-Based Hallucination Detection in RAG Systems17 Dec 2025
- 2025Embedding Trust: Semantic Isotropy Predicts Nonfactuality in Long-Form Text Generation24 Oct 2025
- 2025PRISM: Phase-enhanced Radial-based Image Signature Mapping framework for fingerprinting AI-generated images18 Sep 2025