Null Controllability for Backward Stochastic Parabolic Convection-Diffusion Equations with Dynamic Boundary Conditions
Mahmoud Baroun, Said Boulite, Abdellatif Elgrou, Lahcen Maniar
TL;DR
The paper addresses null controllability for backward stochastic parabolic equations with dynamic boundary conditions and convection. It develops a new global Carleman estimate for forward stochastic parabolic equations with weak divergence terms and uses duality to derive an observability inequality for the adjoint problem, enabling null controllability and explicit cost bounds. A penalized Hilbert Uniqueness Method links controllability of the backward system to properties of the forward adjoint equation, and the results extend to dynamic boundary conditions with surface diffusion. The approach yields an $e^{CT^{-1}}$-type observability constant for small times and provides a constructive way to obtain null controls with quantified energy costs, advancing the theory of SPDE controllability under complex boundary interactions.
Abstract
This paper is concerned with the null controllability for linear backward stochastic parabolic equations with dynamic boundary conditions and convection terms. Using the classical duality argument, the null controllability is obtained via an appropriate observability inequality of the corresponding adjoint forward stochastic parabolic equation. To prove this observability inequality, we develop a new global Carleman estimate for forward stochastic parabolic equations that contains some first-order terms in the weak divergence form. Our Carleman estimate is established by applying the duality technique. Moreover, an estimate of the null-control cost is provided.
