# Learning Optimal Deterministic Policies with Stochastic Policy Gradients

arXiv: https://arxiv.org/abs/2405.02235 · HTML: https://mlsanity.com/paper/2405.02235/

## Key facts

- Cited by 12 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 24 of its 56 references that are in the map.
- First posted on arXiv 3 May 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, 24 of 24)

- [Addressing Function Approximation Error in Actor-Critic Methods](https://mlsanity.com/paper/1802.09477/) (2018)
- [Linear Convergence of Gradient and Proximal-Gradient Methods Under the Polyak-Lojasiewicz Condition](https://mlsanity.com/paper/1608.04636/) (2016)
- [Benchmarking Deep Reinforcement Learning for Continuous Control](https://mlsanity.com/paper/1604.06778/) (2016)
- [Lower Bounds for Non-Convex Stochastic Optimization](https://mlsanity.com/paper/1912.02365/) (2019)
- [On the Global Convergence Rates of Softmax Policy Gradient Methods](https://mlsanity.com/paper/2005.06392/) (2020)
- [Global Convergence of Policy Gradient Methods for the Linear Quadratic Regulator](https://mlsanity.com/paper/1801.05039/) (2018)
- [Understanding the impact of entropy on policy optimization](https://mlsanity.com/paper/1811.11214/) (2018)
- [Global Optimality Guarantees For Policy Gradient Methods](https://mlsanity.com/paper/1906.01786/) (2019)
- [Adaptive Trust Region Policy Optimization: Global Convergence and Faster Rates for Regularized MDPs](https://mlsanity.com/paper/1909.02769/) (2019)
- [Stochastic Variance-Reduced Policy Gradient](https://mlsanity.com/paper/1806.05618/) (2018)
- [A general sample complexity analysis of vanilla policy gradient](https://mlsanity.com/paper/2107.11433/) (2021)
- [An Improved Analysis of (Variance-Reduced) Policy Gradient and Natural Policy Gradient Methods](https://mlsanity.com/paper/2211.07937/) (2022)
- [Sample Efficient Policy Gradient Methods with Recursive Variance Reduction](https://mlsanity.com/paper/1909.08610/) (2019)
- [An Improved Convergence Analysis of Stochastic Variance-Reduced Policy Gradient](https://mlsanity.com/paper/1905.12615/) (2019)
- [Stochastic Policy Gradient Methods: Improved Sample Complexity for Fisher-non-degenerate Policies](https://mlsanity.com/paper/2302.01734/) (2023)
- [Softmax Policy Gradient Methods Can Take Exponential Time to Converge](https://mlsanity.com/paper/2102.11270/) (2021)
- [Policy Optimization via Importance Sampling](https://mlsanity.com/paper/1809.06098/) (2018)
- [Second-Order Information in Non-Convex Stochastic Optimization: Power and Limitations](https://mlsanity.com/paper/2006.13476/) (2020)
- [On the Global Optimum Convergence of Momentum-based Policy Gradient](https://mlsanity.com/paper/2110.10116/) (2021)
- [Smoothing Policies and Safe Policy Gradients](https://mlsanity.com/paper/1905.03231/) (2019)
- [Stochastic Second-Order Methods Improve Best-Known Sample Complexity of SGD for Gradient-Dominated Function](https://mlsanity.com/paper/2205.12856/) (2022)
- [Zeroth-order Deterministic Policy Gradient](https://mlsanity.com/paper/2006.07314/) (2020)
- [Policy Gradient Algorithms Implicitly Optimize by Continuation](https://mlsanity.com/paper/2305.06851/) (2023)
- [Truly Deterministic Policy Optimization](https://mlsanity.com/paper/2205.15379/) (2022)

## Built on by (most cited first, 12 of 12)

- [From Parameters to Behaviors: Unsupervised Compression of the Policy Space](https://mlsanity.com/paper/2509.22566/) (2025)
- [Last-Iterate Global Convergence of Policy Gradients for Constrained Reinforcement Learning](https://mlsanity.com/paper/2407.10775/) (2024)
- [Reusing Trajectories in Policy Gradients Enables Fast Convergence](https://mlsanity.com/paper/2506.06178/) (2025)
- [How Log-Barrier Helps Exploration in Policy Optimization](https://mlsanity.com/paper/2603.15001/) (2026)
- [Unsupervised Behavioral Compression: Learning Low-Dimensional Policy Manifolds through State-Occupancy Matching](https://mlsanity.com/paper/2603.27044/) (2026)
- [Deterministic Policy Gradient Primal-Dual Methods for Continuous-Space Constrained MDPs](https://mlsanity.com/paper/2408.10015/) (2024)
- [Contraction-Aware Reinforcement Learning for Nonlinear Control with Statistical Robustness](https://mlsanity.com/paper/2506.15700/) (2025)
- [Analyzing Symbolic Properties for DRL Agents in Systems and Networking](https://mlsanity.com/paper/2604.04914/) (2026)
- [An Actor-Critic Framework for Continuous-Time Jump-Diffusion Controls with Normalizing Flows](https://mlsanity.com/paper/2604.05398/) (2026)
- [SafePG: Safe and Globally Optimal Reinforcement Learning with Hard Constraints](https://mlsanity.com/paper/2609.14076/) (2026)
- [Bellman-Certified Rounding for Sparse Policy Deployment in MDPs](https://mlsanity.com/paper/2610.00325/) (2026)
- [Variance-Reduced Policy Gradient is Nearly Minimax-Optimal](https://mlsanity.com/paper/2610.13692/) (2026)

## Abstract (arXiv)

Policy gradient (PG) methods are successful approaches to deal with continuous reinforcement learning (RL) problems. They learn stochastic parametric (hyper)policies by either exploring in the space of actions or in the space of parameters. Stochastic controllers, however, are often undesirable from a practical perspective because of their lack of robustness, safety, and traceability. In common practice, stochastic (hyper)policies are learned only to deploy their deterministic version. In this paper, we make a step towards the theoretical understanding of this practice. After introducing a novel framework for modeling this scenario, we study the global convergence to the best deterministic policy, under (weak) gradient domination assumptions. Then, we illustrate how to tune the exploration level used for learning to optimize the trade-off between the sample complexity and the performance of the deployed deterministic policy. Finally, we quantitatively compare action-based and parameter-based exploration, giving a formal guise to intuitive results.
