Well-Posedness and Efficient Algorithms for Inverse Optimal Transport with Bregman Regularization
Chenglong Bao, Zanyu Li, Yunan Yang
TL;DR
This paper develops a comprehensive theory and scalable algorithm for inverse optimal transport with general Bregman regularization. It establishes existence, (equivalence-class) uniqueness, and stability of recovered costs via a forward Bregman-regularized OT map, and provides a generalized single-level convex reformulation of the inverse problem. A practical inexact block coordinate descent algorithm with linear convergence is proposed, leveraging quadratic penalties to enable diagonal-Hessian subproblems and fast Newton updates. Numerical experiments on synthetic data and a real-world marriage matching task demonstrate stable recovery and favorable computational performance, while sensitivity analyses reveal how regularization choices and parameters affect outcomes.
Abstract
This work analyzes the inverse optimal transport (IOT) problem under Bregman regularization. We establish well-posedness results, including existence, uniqueness (up to equivalence classes of solutions), and stability, under several structural assumptions on the cost matrix. On the computational side, we investigate the existence of solutions to the optimization problem with general constraints on the cost matrix and provide a sufficient condition guaranteeing existence. In addition, we propose an inexact block coordinate descent (BCD) method for the problem with a strongly convex penalty term. In particular, when the penalty is quadratic, the subproblems admit a diagonal Hessian structure, which enables highly efficient element-wise Newton updates. We establish a linear convergence rate for the algorithm and demonstrate its practical performance through numerical experiments, including the validation of stability bounds, the investigation of regularization effects, and the application to a marriage matching dataset.
