On the Hopf-Cole Transform for Control-affine Schrödinger Bridge

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Teter, Alexis, Halder, Abhishek
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866915212864520192
author Teter, Alexis
Halder, Abhishek
author_facet Teter, Alexis
Halder, Abhishek
contents The purpose of this note is to clarify the importance of the relation $\boldsymbol{gg}^{\top}\propto \boldsymbol{σσ}^{\top}$ in solving control-affine Schrödinger bridge problems via the Hopf-Cole transform, where $\boldsymbol{g},\boldsymbolσ$ are the control and noise coefficients, respectively. We show that the Hopf-Cole transform applied to the conditions of optimality for generic control-affine Schrödinger bridge problems, i.e., without the assumption $\boldsymbol{gg}^{\top}\propto\boldsymbol{σσ}^{\top}$, gives a pair of forward-backward PDEs that are neither linear nor equation-level decoupled. We explain how the resulting PDEs can be interpreted as nonlinear forward-backward advection-diffusion-reaction equations, where the nonlinearity stem from additional drift and reaction terms involving the gradient of the log-likelihood a.k.a. the score. These additional drift and reaction vanish when $\boldsymbol{gg}^{\top}\propto\boldsymbol{σσ}^{\top}$, and the resulting boundary-coupled system of linear PDEs can then be solved by dynamic Sinkhorn recursions. A key takeaway of our work is that the numerical solution of the generic control-affine Schrödinger bridge requires further algorithmic development, possibly generalizing the dynamic Sinkhorn recursion or otherwise.
format Preprint
id arxiv_https___arxiv_org_abs_2503_17640
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the Hopf-Cole Transform for Control-affine Schrödinger Bridge
Teter, Alexis
Halder, Abhishek
Optimization and Control
Artificial Intelligence
Machine Learning
Systems and Control
The purpose of this note is to clarify the importance of the relation $\boldsymbol{gg}^{\top}\propto \boldsymbol{σσ}^{\top}$ in solving control-affine Schrödinger bridge problems via the Hopf-Cole transform, where $\boldsymbol{g},\boldsymbolσ$ are the control and noise coefficients, respectively. We show that the Hopf-Cole transform applied to the conditions of optimality for generic control-affine Schrödinger bridge problems, i.e., without the assumption $\boldsymbol{gg}^{\top}\propto\boldsymbol{σσ}^{\top}$, gives a pair of forward-backward PDEs that are neither linear nor equation-level decoupled. We explain how the resulting PDEs can be interpreted as nonlinear forward-backward advection-diffusion-reaction equations, where the nonlinearity stem from additional drift and reaction terms involving the gradient of the log-likelihood a.k.a. the score. These additional drift and reaction vanish when $\boldsymbol{gg}^{\top}\propto\boldsymbol{σσ}^{\top}$, and the resulting boundary-coupled system of linear PDEs can then be solved by dynamic Sinkhorn recursions. A key takeaway of our work is that the numerical solution of the generic control-affine Schrödinger bridge requires further algorithmic development, possibly generalizing the dynamic Sinkhorn recursion or otherwise.
title On the Hopf-Cole Transform for Control-affine Schrödinger Bridge
topic Optimization and Control
Artificial Intelligence
Machine Learning
Systems and Control
url https://arxiv.org/abs/2503.17640