English

The Pontryagin maximum principle and $Q$-functions in rough environments

Optimization and Control 2026-01-12 v1 Probability

Abstract

We derive the Pontryagin maximum principle and QQ-functions for the relaxed control of noisy rough differential equations. Our main tool is the development of a novel differentiation procedure along `spike variation' perturbations of the optimal state-control pair. We then exploit our development of the infinitesimal QQ-function (also known as the qq-function) to derive a policy improvement algorithm for settings with entropic cost constraints.

Keywords

Cite

@article{arxiv.2601.05354,
  title  = {The Pontryagin maximum principle and $Q$-functions in rough environments},
  author = {Estepan Ashkarian and Prakash Chakraborty and Harsha Honnappa and Samy Tindel},
  journal= {arXiv preprint arXiv:2601.05354},
  year   = {2026}
}