Exact controllability of anisotropic 1D partial differential equations in spaces of analytic functions
Camille Laurent, Ivonne Rivas, Lionel Rosier
TL;DR
This work addresses exact controllability for a broad class of anisotropic 1D PDEs on $[0,1]$ with higher spatial order than temporal order, proving local controllability between analytic states under natural compatibility conditions. The authors develop a nonlinear Cauchy problem in the spatial variable within Gevrey spaces and establish a precise jet-derivative correspondence between space and time to enable forward and backward evolution. They prove a local controllability result with explicit Gevrey regularity $y\in G^{1,\lambda}([0,1]\times[0,T])$ (where $\lambda=M/N>1$) and provide a comprehensive set of applications to models such as KdV, Boussinesq, complex Ginzburg-Landau, and Kuramoto-Sivashinsky, as well as linear constant-coefficient PDEs. The paper also develops a Gevrey-functional framework, compatibility sets, and a complex-analytic toolkit, enabling the extension of the approach to complex-valued equations. Overall, the work advances controllability theory for ill-posed-looking problems by exploiting spatial Cauchy-analysis and analytic data to achieve precise, high-regularity controllability results.
Abstract
In this article, we prove a local controllability result for a general class of 1D partial differential equations on the interval $(0,1)$. The PDEs we consider take the form $\partial_t^N y=ζ_M \partial_{x}^{M}y+f(x , y , \partial_{x} y,\ldots, \partial_x^{M-1} y)$ where $1\le N < M$, $ζ_M\in \mathbb{C} ^*$, and $f$ is some linear or nonlinear term of lower order. In this context, we prove a local controllability result between states that are analytic functions. If some boundary conditions are prescribed, a similar local controllability result holds between analytic functions satisfying some compatibility conditions that are natural for the existence of smooth solutions of the considered PDE. The proof is performed by studying a nonlinear Cauchy problem in the spatial variable with data in some spaces of Gevrey functions and by investigating the relationship between the jet of space derivatives and the jet of time derivatives. We give various examples of applications, including the (good and bad) Boussinesq equation, the Ginzburg-Landau equation, the Kuramoto-Sivashinsky equation and the Korteweg-de Vries equation.
