HyperRAG-IHM: Incremental Hyperedge Maintenance for Hypergraph RAG under Corpus Expansion

Haoyu Chen, Jihua Zhu, Tingkai Jia, Shengwei Zhao, Lin Chen, Xiaoxuan Mu


Abstract
Hypergraph-based methods extend structured retrieval-augmented generation (RAG) by organizing external knowledge as multi-entity relational structures, helping large language models (LLMs) generate better-grounded answers. However, existing structured RAG systems typically assume static corpus construction, requiring the retrieval structure to be rebuilt over the expanded corpus when new documents arrive. To address this limitation, we introduce HyperRAG-IHM, a hypergraph-based RAG framework that performs incremental hyperedge maintenance to incorporate newly arriving knowledge without reconstructing the historical retrieval structure. HyperRAG-IHM links relational evidence extracted from new documents to existing hypergraph knowledge, avoiding reconstruction of the entire retrieval structure. It uses LSH to localize candidate historical hyperedges, then applies multi-dimensional comparison and a three-action decision policy to integrate new relational evidence. Experiments show that HyperRAG-IHM achieves answer quality comparable to or better than full reconstruction under 5D scoring and 8D pairwise evaluation, and remains robust across ablation, structural behavior, cross-dataset, and cross-answer-model analyses.
Anthology ID:
2026.emnlp-main.898
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
20682–20693
Language:
URL:
https://aclanthology.org/2026.emnlp-main.898/
DOI:
Bibkey:
Cite (ACL):
Haoyu Chen, Jihua Zhu, Tingkai Jia, Shengwei Zhao, Lin Chen, and Xiaoxuan Mu. 2026. HyperRAG-IHM: Incremental Hyperedge Maintenance for Hypergraph RAG under Corpus Expansion. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 20682–20693, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
HyperRAG-IHM: Incremental Hyperedge Maintenance for Hypergraph RAG under Corpus Expansion (Chen et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.898.pdf