Reject, Resample, Repeat: Understanding Parallel Reasoning in Language Model Inference
On the map: LLM reasoning → Test-time compute and efficient thinking
Abstract (arXiv)
Inference-time methods that aggregate and prune multiple samples have emerged as a powerful paradigm for steering large language models, yet we lack any principled understanding of their accuracy-cost tradeoffs. In this paper, we introduce a route to rigorously study such approaches using the lens of *particle filtering* algorithms such as Sequential Monte Carlo (SMC). Given a base language model and a *process reward model* estimating expected terminal rewards, we ask: *how accurately can we sample from a target distribution given some number of process reward evaluations?* Theoretically, we identify (1) simple criteria enabling non-asymptotic guarantees for SMC; (2) algorithmic improvements to SMC; and (3) a fundamental limit faced by all particle filtering methods. Empirically, we demonstrate that our theoretical criteria effectively govern the *sampling error* of SMC, though not necessarily its final *accuracy*, suggesting that theoretical perspectives beyond sampling may be necessary.
Key facts. Cited by 2 papers in the map (data through 7 Oct 2026). Placed in Test-time compute and efficient thinking, one of 17 directions in LLM reasoning. Builds on 36 of its 47 references that are in the map. First posted on arXiv 9 Mar 2026.
Builds on
36 of 47 references.
Closest ancestors · 9
Same direction, newest first
- 2026On the Power of (Approximate) Reward Models for Inference-Time Scaling1 Feb
- 2025On the Limits of Test-Time Compute: Sequential Reward Filtering for Better Inference4 Dec
- 2025Taming Imperfect Process Verifiers: A Sampling Perspective on Backtracking3 Oct
- 2025Rethinking Thinking Tokens: LLMs as Improvement Operators1 Oct
- 2025Deep Think with Confidence21 Aug
- 2025Value-Guided Search for Efficient Chain-of-Thought Reasoning23 May
- 2025A*-Decoding: Token-Efficient Inference Scaling19 May
- 2025Self-Steering Language Models9 Apr
- 2025On the Query Complexity of Verifier-Assisted Language Generation17 Feb
Other references · 27
- 2022Self-Consistency Improves Chain of Thought Reasoning in Language Modelscited by 5,601
- 2023Let's Verify Step by Stepcited by 3,598
- 2024Large Language Monkeys: Scaling Inference Compute with Repeated Samplingcited by 946
- 2023Math-Shepherd: Verify and Reinforce LLMs Step-by-step without Human Annotationscited by 895
- 2025The Lessons of Developing Process Reward Models in Mathematical Reasoningcited by 402
- 2021FUDGE: Controlled Text Generation With Future Discriminatorscited by 374
- 2023Iterative Preference Learning from Human Feedback: Bridging Theory and Practice for RLHF under KL-Constraintcited by 346
- 2025A General Framework for Inference-time Scaling and Steering of Diffusion Modelscited by 201
- 2023Controlled Decoding from Language Modelscited by 133
- 2025ReSum: Unlocking Long-Horizon Search Intelligence via Context Summarizationcited by 132
- 2024Buffer of Thoughts: Thought-Augmented Reasoning with Large Language Modelscited by 91
- 2024Probabilistic Inference in Language Models via Twisted Sequential Monte Carlocited by 85
15 more
- 2025Feynman-Kac Correctors in Diffusion: Annealing, Guidance, and Product of Expertscited by 85
- 2025Reasoning with Sampling: Your Base Model is Smarter Than You Thinkcited by 84
- 2023Sequential Monte Carlo Steering of Large Language Models using Probabilistic Programscited by 79
- 2025The Majority is not always right: RL training for solution aggregationcited by 46
- 2025Syntactic and Semantic Control of Large Language Models via Sequential Monte Carlocited by 45
- 2025Is a Good Foundation Necessary for Efficient Reinforcement Learning? The Computational Role of the Base Model in Explorationcited by 34
- 2025The Coverage Principle: How Pre-Training Enables Post-Trainingcited by 25
- 2022SIXO: Smoothing Inference with Twisted Objectivescited by 22
- 2024From Calculation to Adjudication: Examining LLM judges on Mathematical Reasoning Taskscited by 22
- 2024Step-by-Step Reasoning for Math Problems via Twisted Sequential Monte Carlocited by 21
- 2025Fast Controlled Generation from Language Models with Adaptive Weighted Rejection Samplingcited by 20
- 2025Guided Speculative Inference for Efficient Test-Time Alignment of LLMscited by 9
- 2016High-dimensional Filtering using Nested Sequential Monte Carlocited by 8
- 2025Sequences of Logits Reveal the Low Rank Structure of Language Modelscited by 8
- 2024Convergence Bounds for Sequential Monte Carlo on Multimodal Distributions using Soft Decompositioncited by 4
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Citing papers per year: 2026: 2.
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- 2025When Life Gives You Samples: The Benefits of Scaling up Inference Compute for Multilingual LLMs
- 2025Mitigating Premature Exploitation in Particle-based Monte Carlo for Inference-Time Scaling
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- 2024Keep Guessing? When Considering Inference Scaling, Mind the Baselines