English

A parallel framework for graphical optimal transport

Optimization and Control 2025-12-02 v2 Computational Complexity

Abstract

We study multi-marginal optimal transport (MOT) problems where the underlying cost has a graphical structure. These graphical multi-marginal optimal transport problems have found applications in several domains including traffic flow control, barycenter and regression problems in the Wasserstein space, and Hidden Markov model inference problems. The MOT problem can be approached through two formulations: a single big MOT problem, or coupled minor OT problems. In this paper, we focus on the latter approach and demonstrate its efficiency gain from parallelization. For tree-structured MOT problems, we introduce a novel parallelizable algorithm that significantly reduces computational complexity. Additionally, we adapt this algorithm for general graphs, employing the modified junction trees to enable parallel updates. Our contributions, validated through numerical experiments, offer new avenues for MOT applications and establish benchmarks in computational efficiency.

Keywords

Cite

@article{arxiv.2406.10849,
  title  = {A parallel framework for graphical optimal transport},
  author = {Jiaojiao Fan and Isabel Haasler and Qinsheng Zhang and Johan Karlsson and Yongxin Chen},
  journal= {arXiv preprint arXiv:2406.10849},
  year   = {2025}
}
R2 v1 2026-06-28T17:07:35.140Z