Efficient Temporal-aware Matryoshka Adaptation for Temporal Information Retrieval

Tuan-Luc Huynh, Weiqing Wang, Trung Le, Thuy-Trang Vu, Dragan Gasevic, Yuan-Fang Li, Thanh-Toan Do


Abstract
Retrievers are a key bottleneck in temporal Retrieval-Augmented Generation (RAG) systems: failing to retrieve temporally relevant context can degrade downstream generation, regardless of LLM reasoning. We propose Temporal-aware Matryoshka Representation Learning (TMRL), an efficient method that equips retrievers with temporal-aware Matryoshka embeddings. TMRL leverages the nested structure of Matryoshka embeddings to introduce a temporal subspace, enhancing temporal encoding while preserving general semantic representations. Experiments show that TMRL efficiently adapts diverse standard encoder-only text embedding models, achieving competitive temporal retrieval and temporal RAG performance compared to existing Matryoshka-based adaptation and temporal retrieval methods, while enabling flexible accuracy-efficiency trade-offs.
Anthology ID:
2026.emnlp-main.249
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:
5677–5701
Language:
URL:
https://aclanthology.org/2026.emnlp-main.249/
DOI:
Bibkey:
Cite (ACL):
Tuan-Luc Huynh, Weiqing Wang, Trung Le, Thuy-Trang Vu, Dragan Gasevic, Yuan-Fang Li, and Thanh-Toan Do. 2026. Efficient Temporal-aware Matryoshka Adaptation for Temporal Information Retrieval. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 5677–5701, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Efficient Temporal-aware Matryoshka Adaptation for Temporal Information Retrieval (Huynh et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.249.pdf