2024/04/30 by Maxim Raginsky, Raginsky, Maxim · 1 voice · 1 citation
#math.OC #math.PR
paper · pdf · doi:10.48550/arxiv.2405.00126
We revisit the work of Mitter and Newton on an information-theoretic interpretation of Bayes' formula through the Gibbs variational principle. This formulation allowed them to pose nonlinear estimation for diffusion processes as a problem in stochastic optimal control, so that the posterior density of the signal given the observation path could be sampled by adding a drift to the signal process. We show that this control-theoretic approach to sampling provides a common mechanism underlying several distinct problems involving diffusion processes, specifically importance sampling using Feynman-Kac averages, time reversal, and Schrödinger bridges.