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Related papers: Off-Policy Actor-Critic with Emphatic Weightings

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Large scale reinforcement learning has become a central tool for improving reasoning in large language models. At this scale, generation is often lagged or asynchronous, so updates are performed on data collected by older policies. This…

Machine Learning · Computer Science 2026-05-28 Otmane Sakhi , Aleksei Arzhantsev , Imad Aouali , Flavian Vasile

We revisit the Reinforce policy gradient algorithm from the literature. Note that this algorithm typically works with cost returns obtained over random length episodes obtained from either termination upon reaching a goal state (as with…

Machine Learning · Computer Science 2023-10-10 Shalabh Bhatnagar

In cooperative stochastic games multiple agents work towards learning joint optimal actions in an unknown environment to achieve a common goal. In many real-world applications, however, constraints are often imposed on the actions that can…

Multiagent Systems · Computer Science 2020-07-14 Raghuram Bharadwaj Diddigi , Sai Koti Reddy Danda , Prabuchandran K. J. , Shalabh Bhatnagar

Deep Reinforcement Learning (DRL) algorithms for continuous action spaces are known to be brittle toward hyperparameters as well as \cut{being}sample inefficient. Soft Actor Critic (SAC) proposes an off-policy deep actor critic algorithm…

Machine Learning · Computer Science 2019-06-10 Patrick Nadeem Ward , Ariella Smofsky , Avishek Joey Bose

We reformulate the option framework as two parallel augmented MDPs. Under this novel formulation, all policy optimization algorithms can be used off the shelf to learn intra-option policies, option termination conditions, and a master…

Machine Learning · Computer Science 2019-09-12 Shangtong Zhang , Shimon Whiteson

Reinforcement learning is a promising approach to learning robotics controllers. It has recently been shown that algorithms based on finite-difference estimates of the policy gradient are competitive with algorithms based on the policy…

Machine Learning · Computer Science 2021-10-12 Osbert Bastani

In reinforcement learning, off-policy evaluation (OPE) is the problem of estimating the expected return of an evaluation policy given a fixed dataset that was collected by running one or more different policies. One of the more empirically…

Machine Learning · Computer Science 2023-10-31 Brahma S. Pavse , Josiah P. Hanna

Actor-critic (AC) is a powerful method for learning an optimal policy in reinforcement learning, where the critic uses algorithms, e.g., temporal difference (TD) learning with function approximation, to evaluate the current policy and the…

Machine Learning · Computer Science 2024-06-05 Yudan Wang , Yue Wang , Yi Zhou , Shaofeng Zou

Actor-critic methods, a type of model-free Reinforcement Learning, have been successfully applied to challenging tasks in continuous control, often achieving state-of-the art performance. However, wide-scale adoption of these methods in…

Machine Learning · Statistics 2019-10-29 Kamil Ciosek , Quan Vuong , Robert Loftin , Katja Hofmann

In this paper, we develop a novel variant of off-policy natural actor-critic algorithm with linear function approximation and we establish a sample complexity of $\mathcal{O}(\epsilon^{-3})$, outperforming all the previously known…

Machine Learning · Computer Science 2022-04-13 Zaiwei Chen , Sajad Khodadadian , Siva Theja Maguluri

While there is an extensive body of research analyzing policy gradient methods for discounted cumulative-reward MDPs, prior work on policy gradient methods for average-reward MDPs has been limited, with most existing results restricted to…

Optimization and Control · Mathematics 2026-02-23 Jongmin Lee , Ernest K. Ryu

We study the problem of off-policy evaluation (OPE) in Reinforcement Learning (RL), where the aim is to estimate the performance of a new policy given historical data that may have been generated by a different policy, or policies. In…

Machine Learning · Computer Science 2019-12-16 Aurélien F. Bibaut , Ivana Malenica , Nikos Vlassis , Mark J. van der Laan

In real-world recommender systems and search engines, optimizing ranking decisions to present a ranked list of relevant items is critical. Off-policy evaluation (OPE) for ranking policies is thus gaining a growing interest because it…

Machine Learning · Statistics 2022-02-04 Haruka Kiyohara , Yuta Saito , Tatsuya Matsuhiro , Yusuke Narita , Nobuyuki Shimizu , Yasuo Yamamoto

Multi-Agent Policy Gradient (MAPG) has made significant progress in recent years. However, centralized critics in state-of-the-art MAPG methods still face the centralized-decentralized mismatch (CDM) issue, which means sub-optimal actions…

Multiagent Systems · Computer Science 2024-01-17 Xingzhou Lou , Junge Zhang , Timothy J. Norman , Kaiqi Huang , Yali Du

We study the problem of offline policy optimization in stochastic contextual bandit problems, where the goal is to learn a near-optimal policy based on a dataset of decision data collected by a suboptimal behavior policy. Rather than making…

Machine Learning · Computer Science 2023-09-28 Germano Gabbianelli , Gergely Neu , Matteo Papini

Although actor-critic methods have been successful in practice, their theoretical analyses have several limitations. Specifically, existing theoretical work either sidesteps the exploration problem by making strong assumptions or analyzes…

Machine Learning · Computer Science 2026-04-02 Max Qiushi Lin , Reza Asad , Kevin Tan , Haque Ishfaq , Csaba Szepesvari , Sharan Vaswani

We consider the estimation of the policy gradient in partially observable Markov decision processes (POMDP) with a special class of structured policies that are finite-state controllers. We show that the gradient estimation can be done in…

Machine Learning · Computer Science 2012-07-09 Huizhen Yu

The option framework has shown great promise by automatically extracting temporally-extended sub-tasks from a long-horizon task. Methods have been proposed for concurrently learning low-level intra-option policies and high-level option…

Artificial Intelligence · Computer Science 2020-06-26 Chenghao Li , Xiaoteng Ma , Chongjie Zhang , Jun Yang , Li Xia , Qianchuan Zhao

In recent years, deep off-policy actor-critic algorithms have become a dominant approach to reinforcement learning for continuous control. One of the primary drivers of this improved performance is the use of pessimistic value updates to…

Machine Learning · Computer Science 2022-04-07 Ted Moskovitz , Jack Parker-Holder , Aldo Pacchiano , Michael Arbel , Michael I. Jordan

We introduce an Actor-Critic Ensemble(ACE) method for improving the performance of Deep Deterministic Policy Gradient(DDPG) algorithm. At inference time, our method uses a critic ensemble to select the best action from proposals of multiple…

Machine Learning · Computer Science 2017-12-29 Zhewei Huang , Shuchang Zhou , BoEr Zhuang , Xinyu Zhou