Latent Spherical Flow Policy for Reinforcement Learning with Combinatorial Actions

Fuente: arXiv
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Main Authors: Kong, Lingkai, Satish, Anagha, Jiang, Hezi, Kangaslahti, Akseli, Ma, Andrew, Chen, Wenbo, Song, Mingxiao, Xu, Lily, Tambe, Milind
Format: Preprint
Published: 2026
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author Kong, Lingkai
Satish, Anagha
Jiang, Hezi
Kangaslahti, Akseli
Ma, Andrew
Chen, Wenbo
Song, Mingxiao
Xu, Lily
Tambe, Milind
author_facet Kong, Lingkai
Satish, Anagha
Jiang, Hezi
Kangaslahti, Akseli
Ma, Andrew
Chen, Wenbo
Song, Mingxiao
Xu, Lily
Tambe, Milind
contents Reinforcement learning (RL) with combinatorial action spaces remains challenging because feasible action sets are exponentially large and governed by complex feasibility constraints, making direct policy parameterization impractical. Existing approaches embed task-specific value functions into constrained optimization programs or learn deterministic structured policies, sacrificing generality and policy expressiveness. We propose a solver-induced \emph{latent spherical flow policy} that brings the expressiveness of modern generative policies to combinatorial RL while guaranteeing feasibility by design. Our method, LSFlow, learns a \emph{stochastic} policy in a compact continuous latent space via spherical flow matching, and delegates feasibility to a combinatorial optimization solver that maps each latent sample to a valid structured action. To improve efficiency, we train the value network directly in the latent space, avoiding repeated solver calls during policy optimization. To address the piecewise-constant and discontinuous value landscape induced by solver-based action selection, we introduce a smoothed Bellman operator that yields stable, well-defined learning targets. Empirically, our approach outperforms state-of-the-art baselines by an average of 20.6\% across a range of challenging combinatorial RL tasks.
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id arxiv_https___arxiv_org_abs_2601_22211
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Latent Spherical Flow Policy for Reinforcement Learning with Combinatorial Actions
Kong, Lingkai
Satish, Anagha
Jiang, Hezi
Kangaslahti, Akseli
Ma, Andrew
Chen, Wenbo
Song, Mingxiao
Xu, Lily
Tambe, Milind
Machine Learning
Reinforcement learning (RL) with combinatorial action spaces remains challenging because feasible action sets are exponentially large and governed by complex feasibility constraints, making direct policy parameterization impractical. Existing approaches embed task-specific value functions into constrained optimization programs or learn deterministic structured policies, sacrificing generality and policy expressiveness. We propose a solver-induced \emph{latent spherical flow policy} that brings the expressiveness of modern generative policies to combinatorial RL while guaranteeing feasibility by design. Our method, LSFlow, learns a \emph{stochastic} policy in a compact continuous latent space via spherical flow matching, and delegates feasibility to a combinatorial optimization solver that maps each latent sample to a valid structured action. To improve efficiency, we train the value network directly in the latent space, avoiding repeated solver calls during policy optimization. To address the piecewise-constant and discontinuous value landscape induced by solver-based action selection, we introduce a smoothed Bellman operator that yields stable, well-defined learning targets. Empirically, our approach outperforms state-of-the-art baselines by an average of 20.6\% across a range of challenging combinatorial RL tasks.
title Latent Spherical Flow Policy for Reinforcement Learning with Combinatorial Actions
topic Machine Learning
url https://arxiv.org/abs/2601.22211