SPARC-RAG: Adaptive Sequential-Parallel Scaling with Context Management for Retrieval-Augmented Generation

Fuente: arXiv
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Main Authors: Yang, Yuxin, Deng, Gangda, Akgül, Ömer Faruk, Chitsazan, Nima, Govilkar, Yash, Tigalappanavara, Akasha, Zhang, Shi-Xiong, Sahu, Sambit, Prasanna, Viktor
Format: Preprint
Published: 2026
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author Yang, Yuxin
Deng, Gangda
Akgül, Ömer Faruk
Chitsazan, Nima
Govilkar, Yash
Tigalappanavara, Akasha
Zhang, Shi-Xiong
Sahu, Sambit
Prasanna, Viktor
author_facet Yang, Yuxin
Deng, Gangda
Akgül, Ömer Faruk
Chitsazan, Nima
Govilkar, Yash
Tigalappanavara, Akasha
Zhang, Shi-Xiong
Sahu, Sambit
Prasanna, Viktor
contents Retrieval-Augmented Generation (RAG) grounds large language model outputs in external evidence, but remains challenged on multi-hop question answering that requires long reasoning. Recent works scale RAG at inference time along two complementary dimensions: sequential depth for iterative refinement and parallel width for coverage expansion. However, naive scaling causes context contamination and scaling inefficiency, leading to diminishing or negative returns despite increased computation. To address these limitations, we propose SPARC-RAG, a multi-agent framework that coordinates sequential and parallel inference-time scaling under a unified context management mechanism. SPARC-RAG employs specialized agents that maintain a shared global context and provide explicit control over the scaling process. It generates targeted, complementary sub-queries for each branch to enable diverse parallel exploration, and explicitly regulates exiting decisions based on answer correctness and evidence grounding. To optimize scaling behavior, we further introduce a lightweight fine-tuning method with process-level verifiable preferences, which improves the efficiency of sequential scaling and effectiveness of parallel scaling. Across single- and multi-hop QA benchmarks, SPARC-RAG consistently outperforms previous RAG baselines, yielding an average +6.2 F1 improvement under lower inference cost.
format Preprint
id arxiv_https___arxiv_org_abs_2602_00083
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle SPARC-RAG: Adaptive Sequential-Parallel Scaling with Context Management for Retrieval-Augmented Generation
Yang, Yuxin
Deng, Gangda
Akgül, Ömer Faruk
Chitsazan, Nima
Govilkar, Yash
Tigalappanavara, Akasha
Zhang, Shi-Xiong
Sahu, Sambit
Prasanna, Viktor
Information Retrieval
Artificial Intelligence
Computation and Language
Machine Learning
Retrieval-Augmented Generation (RAG) grounds large language model outputs in external evidence, but remains challenged on multi-hop question answering that requires long reasoning. Recent works scale RAG at inference time along two complementary dimensions: sequential depth for iterative refinement and parallel width for coverage expansion. However, naive scaling causes context contamination and scaling inefficiency, leading to diminishing or negative returns despite increased computation. To address these limitations, we propose SPARC-RAG, a multi-agent framework that coordinates sequential and parallel inference-time scaling under a unified context management mechanism. SPARC-RAG employs specialized agents that maintain a shared global context and provide explicit control over the scaling process. It generates targeted, complementary sub-queries for each branch to enable diverse parallel exploration, and explicitly regulates exiting decisions based on answer correctness and evidence grounding. To optimize scaling behavior, we further introduce a lightweight fine-tuning method with process-level verifiable preferences, which improves the efficiency of sequential scaling and effectiveness of parallel scaling. Across single- and multi-hop QA benchmarks, SPARC-RAG consistently outperforms previous RAG baselines, yielding an average +6.2 F1 improvement under lower inference cost.
title SPARC-RAG: Adaptive Sequential-Parallel Scaling with Context Management for Retrieval-Augmented Generation
topic Information Retrieval
Artificial Intelligence
Computation and Language
Machine Learning
url https://arxiv.org/abs/2602.00083