English

On the Martingale Schr\"odinger Bridge between Two Distributions

Probability 2025-09-01 v2 Mathematical Finance

Abstract

We study a martingale Schr\"odinger bridge problem: given two probability distributions, find their martingale coupling with minimal relative entropy. Our main result provides Schr\"odinger potentials for this coupling. Namely, under certain conditions, the log-density of the optimal coupling is given by a triplet of real functions representing the marginal and martingale constraints. The potentials are also described as the solution of a dual problem.

Keywords

Cite

@article{arxiv.2401.05209,
  title  = {On the Martingale Schr\"odinger Bridge between Two Distributions},
  author = {Marcel Nutz and Johannes Wiesel},
  journal= {arXiv preprint arXiv:2401.05209},
  year   = {2025}
}

Comments

Final version, accepted for publication in Bernoulli

R2 v1 2026-06-28T14:13:17.358Z