# Efficient Model-Free Exploration in Low-Rank MDPs

arXiv: https://arxiv.org/abs/2307.03997 · HTML: https://mlsanity.com/paper/2307.03997/

## Key facts

- Cited by 16 papers in the map (data through 14 Oct 2026).
- Builds on 32 of its 46 references that are in the map.
- First posted on arXiv 8 Jul 2023.

## Builds on (most cited first, 30 of 32)

- [Continuous control with deep reinforcement learning](https://mlsanity.com/paper/1509.02971/) (2015)
- [Provably Efficient Reinforcement Learning with Linear Function Approximation](https://mlsanity.com/paper/1907.05388/) (2019)
- [Minimax Regret Bounds for Reinforcement Learning](https://mlsanity.com/paper/1703.05449/) (2017)
- [Contextual Decision Processes with Low Bellman Rank are PAC-Learnable](https://mlsanity.com/paper/1610.09512/) (2016)
- [Deep Reinforcement Learning for Dialogue Generation](https://mlsanity.com/paper/1606.01541/) (2016)
- [FLAMBE: Structural Complexity and Representation Learning of Low Rank MDPs](https://mlsanity.com/paper/2006.10814/) (2020)
- [Bellman Eluder Dimension: New Rich Classes of RL Problems, and Sample-Efficient Algorithms](https://mlsanity.com/paper/2102.00815/) (2021)
- [The Statistical Complexity of Interactive Decision Making](https://mlsanity.com/paper/2112.13487/) (2021)
- [Bilinear Classes: A Structural Framework for Provable Generalization in RL](https://mlsanity.com/paper/2103.10897/) (2021)
- [Provably efficient RL with Rich Observations via Latent State Decoding](https://mlsanity.com/paper/1901.09018/) (2019)
- [Representation Learning for Online and Offline RL in Low-rank MDPs](https://mlsanity.com/paper/2110.04652/) (2021)
- [Model-Based Reinforcement Learning with a Generative Model is Minimax Optimal](https://mlsanity.com/paper/1906.03804/) (2019)
- [Kinematic State Abstraction and Provably Efficient Rich-Observation Reinforcement Learning](https://mlsanity.com/paper/1911.05815/) (2019)
- [A Short Note on Concentration Inequalities for Random Vectors with SubGaussian Norm](https://mlsanity.com/paper/1902.03736/) (2019)
- [On Reward-Free Reinforcement Learning with Linear Function Approximation](https://mlsanity.com/paper/2006.11274/) (2020)
- [The Role of Coverage in Online Reinforcement Learning](https://mlsanity.com/paper/2210.04157/) (2022)
- [Model-free Representation Learning and Exploration in Low-rank MDPs](https://mlsanity.com/paper/2102.07035/) (2021)
- [On Oracle-Efficient PAC RL with Rich Observations](https://mlsanity.com/paper/1803.00606/) (2018)
- [Feel-Good Thompson Sampling for Contextual Bandits and Reinforcement Learning](https://mlsanity.com/paper/2110.00871/) (2021)
- [Provably Efficient Reward-Agnostic Navigation with Linear Value Iteration](https://mlsanity.com/paper/2008.07737/) (2020)
- [Making Linear MDPs Practical via Contrastive Representation Learning](https://mlsanity.com/paper/2207.07150/) (2022)
- [Efficient Reinforcement Learning in Block MDPs: A Model-free Representation Learning Approach](https://mlsanity.com/paper/2202.00063/) (2022)
- [VOQL: Towards Optimal Regret in Model-free RL with Nonlinear Function Approximation](https://mlsanity.com/paper/2212.06069/) (2022)
- [Provable Benefits of Representational Transfer in Reinforcement Learning](https://mlsanity.com/paper/2205.14571/) (2022)
- [Reinforcement Learning with General Value Function Approximation: Provably Efficient Approach via Bounded Eluder Dimension](https://mlsanity.com/paper/2005.10804/) (2020)
- [Learning in Observable POMDPs, without Computationally Intractable Oracles](https://mlsanity.com/paper/2206.03446/) (2022)
- [Tight Guarantees for Interactive Decision Making with the Decision-Estimation Coefficient](https://mlsanity.com/paper/2301.08215/) (2023)
- [Partially Observable RL with B-Stability: Unified Structural Condition and Sharp Sample-Efficient Algorithms](https://mlsanity.com/paper/2209.14990/) (2022)
- [Representation Learning with Multi-Step Inverse Kinematics: An Efficient and Optimal Approach to Rich-Observation RL](https://mlsanity.com/paper/2304.05889/) (2023)
- [Learning the Linear Quadratic Regulator from Nonlinear Observations](https://mlsanity.com/paper/2010.03799/) (2020)

## Built on by (most cited first, 16 of 16)

- [Overcoming the Sim-to-Real Gap: Leveraging Simulation to Learn to Explore for Real-World RL](https://mlsanity.com/paper/2410.20254/) (2024)
- [Offline Oracle-Efficient Learning for Contextual MDPs via Layerwise Exploration-Exploitation Tradeoff](https://mlsanity.com/paper/2405.17796/) (2024)
- [The Central Role of the Loss Function in Reinforcement Learning](https://mlsanity.com/paper/2409.12799/) (2024)
- [Oracle-Efficient Differentially Private Learning with Public Data](https://mlsanity.com/paper/2402.09483/) (2024)
- [Exploration is Harder than Prediction: Cryptographically Separating Reinforcement Learning from Supervised Learning](https://mlsanity.com/paper/2404.03774/) (2024)
- [Pessimism Meets Risk: Risk-Sensitive Offline Reinforcement Learning](https://mlsanity.com/paper/2407.07631/) (2024)
- [Exploring and Learning in Sparse Linear MDPs without Computationally Intractable Oracles](https://mlsanity.com/paper/2309.09457/) (2023)
- [Projection by Convolution: Optimal Sample Complexity for Reinforcement Learning in Continuous-Space MDPs](https://mlsanity.com/paper/2405.06363/) (2024)
- [Linear Bellman Completeness Suffices for Efficient Online Reinforcement Learning with Few Actions](https://mlsanity.com/paper/2406.11640/) (2024)
- [To Distill or Decide? Understanding the Algorithmic Trade-off in Partially Observable Reinforcement Learning](https://mlsanity.com/paper/2510.03207/) (2025)
- [Beating Adversarial Low-Rank MDPs with Unknown Transition and Bandit Feedback](https://mlsanity.com/paper/2411.06739/) (2024)
- [Accelerating Multi-Task Temporal Difference Learning under Low-Rank Representation](https://mlsanity.com/paper/2503.02030/) (2025)
- [Decoupling Exploration and Policy Optimization: Uncertainty Guided Tree Search for Hard Exploration](https://mlsanity.com/paper/2603.22273/) (2026)
- [The Horizon Threshold in Cooperative Multi-Agent Reward-Free Exploration](https://mlsanity.com/paper/2602.01453/) (2026)
- [End-to-End Efficient RL for Linear Bellman Complete MDPs with Deterministic Transitions](https://mlsanity.com/paper/2603.23461/) (2026)
- [Breaking the Computational Barrier: Provably Efficient Actor-Critic for Low-Rank MDPs](https://mlsanity.com/paper/2605.01242/) (2026)

## Abstract (arXiv)

A major challenge in reinforcement learning is to develop practical, sample-efficient algorithms for exploration in high-dimensional domains where generalization and function approximation is required. Low-Rank Markov Decision Processes -- where transition probabilities admit a low-rank factorization based on an unknown feature embedding -- offer a simple, yet expressive framework for RL with function approximation, but existing algorithms are either (1) computationally intractable, or (2) reliant upon restrictive statistical assumptions such as latent variable structure, access to model-based function approximation, or reachability. In this work, we propose the first provably sample-efficient algorithm for exploration in Low-Rank MDPs that is both computationally efficient and model-free, allowing for general function approximation and requiring no additional structural assumptions. Our algorithm, VoX, uses the notion of a barycentric spanner for the feature embedding as an efficiently computable basis for exploration, performing efficient barycentric spanner computation by interleaving representation learning and policy optimization. Our analysis -- which is appealingly simple and modular -- carefully combines several techniques, including a new approach to error-tolerant barycentric spanner computation and an improved analysis of a certain minimax representation learning objective found in prior work.