A stochastic regularized second-order iterative scheme for optimal control and inverse problems in stochastic partial differential equations

Philos Trans A Math Phys Eng Sci. 2022 Nov 14;380(2236):20210352. doi: 10.1098/rsta.2021.0352. Epub 2022 Sep 26.

Abstract

Numerous applied models used in the study of optimal control problems, inverse problems, shape optimization, machine learning, fractional programming, neural networks, image registration and so on lead to stochastic optimization problems in Hilbert spaces. Under a suitable convexity assumption on the objective function, a necessary and sufficient optimality condition for stochastic optimization problems is a stochastic variational inequality. This article presents a new stochastic regularized second-order iterative scheme for solving a variational inequality in a stochastic environment where the primary operator is accessed by employing sampling techniques. The proposed iterative scheme, which fits within the general framework of the stochastic approximation approach, has its almost-sure convergence analysis given in a Hilbert space. We test the feasibility and the efficacy of the proposed stochastic approximation approach for a stochastic optimal control problem and a stochastic inverse problem, both associated with a second-order stochastic partial differential equation. This article is part of the theme issue 'Non-smooth variational problems and applications'.

Keywords: partial differential equations with random data; regularization; stochastic inverse problems; stochastic optimal control; stochastic regularized heavy ball with friction iterative method; stochastic regularized second-order iterative methods.