The Retriever Found Similar Things. The Evidence Was Elsewhere.
TL;DR for operators The current enterprise RAG conversation still has a charmingly stubborn misconception: if the model hallucinates, buy better embeddings, increase the context window, add an agent, and hope the PowerPoint becomes true. The two papers here point in a less theatrical direction. One paper, Non-negative Elastic Net Decoding for Information Retrieval, argues that dense retrieval has a structural weakness: it scores each candidate independently, so it can retrieve several similar items instead of the complementary set actually needed to answer the query.1 The other, Agentic Hybrid RAG for Evidence-Grounded Muon Collider Analysis, shows what happens when retrieval is treated as a full evidence workflow: sparse and dense retrieval are fused, queries are decomposed under constraints, evidence is deduplicated and budgeted, and answers are judged for coverage, hallucination, and abstention.2 ...