# Linear Bellman Completeness Suffices for Efficient Online Reinforcement Learning with Few Actions

arXiv: https://arxiv.org/abs/2406.11640 · HTML: https://mlsanity.com/paper/2406.11640/

## Key facts

- Cited by 4 papers in the map (data through 14 Oct 2026).
- Placed in RL theory and sample complexity, one of 15 directions in Deep reinforcement learning methods.
- Builds on 26 of its 42 references that are in the map.
- First posted on arXiv 17 Jun 2024.

## Placed in

- Deep reinforcement learning methods / [RL theory and sample complexity](https://mlsanity.com/deeprl/rl-theory-and-sample-complexity/)

## Builds on (most cited first, 26 of 26)

- [Proximal Policy Optimization Algorithms](https://mlsanity.com/paper/1707.06347/) (2017)
- [Deep Reinforcement Learning with Double Q-learning](https://mlsanity.com/paper/1509.06461/) (2015)
- [Minimax Regret Bounds for Reinforcement Learning](https://mlsanity.com/paper/1703.05449/) (2017)
- [Reinforcement Learning in Healthcare: A Survey](https://mlsanity.com/paper/1908.08796/) (2019)
- [Contextual Decision Processes with Low Bellman Rank are PAC-Learnable](https://mlsanity.com/paper/1610.09512/) (2016)
- [Bellman Eluder Dimension: New Rich Classes of RL Problems, and Sample-Efficient Algorithms](https://mlsanity.com/paper/2102.00815/) (2021)
- [Reinforcement Learning in Feature Space: Matrix Bandit, Kernels, and Regret Bound](https://mlsanity.com/paper/1905.10389/) (2019)
- [Learning Near Optimal Policies with Low Inherent Bellman Error](https://mlsanity.com/paper/2003.00153/) (2020)
- [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)
- [Almost Optimal Model-Free Reinforcement Learning via Reference-Advantage Decomposition](https://mlsanity.com/paper/2004.10019/) (2020)
- [Kinematic State Abstraction and Provably Efficient Rich-Observation Reinforcement Learning](https://mlsanity.com/paper/1911.05815/) (2019)
- [Generalization and Exploration via Randomized Value Functions](https://mlsanity.com/paper/1402.0635/) (2014)
- [Nearly Minimax Optimal Reinforcement Learning for Linear Markov Decision Processes](https://mlsanity.com/paper/2212.06132/) (2022)
- [Provably Efficient Reward-Agnostic Navigation with Linear Value Iteration](https://mlsanity.com/paper/2008.07737/) (2020)
- [Cautiously Optimistic Policy Optimization and Exploration with Linear Function Approximation](https://mlsanity.com/paper/2103.12923/) (2021)
- [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)
- [Tight Hardness Results for Training Depth-2 ReLU Networks](https://mlsanity.com/paper/2011.13550/) (2020)
- [Learning Two Layer Rectified Neural Networks in Polynomial Time](https://mlsanity.com/paper/1811.01885/) (2018)
- [Learning in Observable POMDPs, without Computationally Intractable Oracles](https://mlsanity.com/paper/2206.03446/) (2022)
- [Representation Learning with Multi-Step Inverse Kinematics: An Efficient and Optimal Approach to Rich-Observation RL](https://mlsanity.com/paper/2304.05889/) (2023)
- [Efficient Reinforcement Learning in Deterministic Systems with Value Function Generalization](https://mlsanity.com/paper/1307.4847/) (2013)
- [Efficient Model-Free Exploration in Low-Rank MDPs](https://mlsanity.com/paper/2307.03997/) (2023)
- [Exploring and Learning in Sparse Linear MDPs without Computationally Intractable Oracles](https://mlsanity.com/paper/2309.09457/) (2023)
- [Exponential Hardness of Reinforcement Learning with Linear Function Approximation](https://mlsanity.com/paper/2302.12940/) (2023)

## Built on by (most cited first, 4 of 4)

- [Optimistically Optimistic Exploration for Provably Efficient Infinite-Horizon Reinforcement and Imitation Learning](https://mlsanity.com/paper/2502.13900/) (2025)
- [Learning Approximate Nash Equilibria in Cooperative Multi-Agent Reinforcement Learning via Mean-Field Subsampling](https://mlsanity.com/paper/2603.03759/) (2026)
- [Frozen Policy Iteration: Computationally Efficient RL under Linear Qπ Realizability for Deterministic Dynamics](https://mlsanity.com/paper/2603.00716/) (2026)
- [End-to-End Efficient RL for Linear Bellman Complete MDPs with Deterministic Transitions](https://mlsanity.com/paper/2603.23461/) (2026)

## Abstract (arXiv)

One of the most natural approaches to reinforcement learning (RL) with function approximation is value iteration, which inductively generates approximations to the optimal value function by solving a sequence of regression problems. To ensure the success of value iteration, it is typically assumed that Bellman completeness holds, which ensures that these regression problems are well-specified. We study the problem of learning an optimal policy under Bellman completeness in the online model of RL with linear function approximation. In the linear setting, while statistically efficient algorithms are known under Bellman completeness (e.g., Jiang et al. (2017); Zanette et al. (2020)), these algorithms all rely on the principle of global optimism which requires solving a nonconvex optimization problem. In particular, it has remained open as to whether computationally efficient algorithms exist. In this paper we give the first polynomial-time algorithm for RL under linear Bellman completeness when the number of actions is any constant.