Critical lengths for the linear Kadomtsev-Petviashvili II equation
Roberto de A. Capistrano-Filho, Fernando Gallego, Ricardo Muñoz
TL;DR
The paper addresses boundary controllability and stabilization of the linear KP-II equation on a rectangle, uncovering a precise critical-length phenomenon connected to Paley–Wiener theory. By proving boundary observability inequalities and employing the Hilbert uniqueness method, it establishes exact boundary controllability and boundary exponential stabilization for lengths $L$ outside an explicitly characterized set $\mathcal{R}$. A Lyapunov-based analysis yields an explicit exponential decay rate, enriching the understanding of dissipative control for dispersive 2D models. The results extend the one-dimensional KdV critical-length theory to KP-II, offering concrete guidelines for control design on rectangular domains and signaling directions for nonlinear KP-II research.
Abstract
The critical length phenomenon of the Korteweg-de Vries equation is well known; however, in higher dimensions, it is unknown. This work explores this property in the context of the Kadomtsev-Petviashvili equation, a two-dimensional generalization of the Korteweg-de Vries equation. Specifically, we demonstrate observability inequalities for this equation, which allow us to deduce the exact boundary controllability and boundary exponential stabilization of the linear system, provided that the spatial domain length avoids certain specific values, a direct consequence of the Paley-Wiener theorem. To the best of our knowledge, our work introduces new results by identifying a set of critical lengths for the two-dimensional Kadomtsev-Petviashvili equation.
