A Mathematical Analysis of a Smooth-Convex-Concave Splitting Scheme for the Swift--Hohenberg Equation
Yuki Yonekura, Daiki Iwade, Shun Sato, Takayasu Matsuo
TL;DR
The paper develops a first-linearly implicit, dissipation-preserving finite-difference scheme for the 3D Swift–Hohenberg equation by a smooth-convex-concave splitting of the energy. It proves unique solvability, a discrete energy-dissipation law, boundedness of numerical solutions, and an a priori error estimate under a time-step restriction, providing a computationally efficient alternative to fully implicit methods. The approach is anchored in discrete convex analysis and a careful handling of energy components, yielding stability and convergence with explicit treatment of nonlinear terms. The results offer a practical, theoretically grounded framework for structure-preserving simulation of the Swift–Hohenberg dynamics in three dimensions.
Abstract
The Swift--Hohenberg equation is a widely studied fourth-order model, originally proposed to describe hydrodynamic fluctuations. It admits an energy-dissipation law and, under suitable assumptions, bounded solutions. Many structure-preserving numerical schemes have been proposed to retain such properties; however, existing approaches are often fully implicit and therefore computationally expensive. We introduce a simple design principle for constructing dissipation-preserving finite difference schemes and apply it to the Swift--Hohenberg equation in three spatial dimensions. Our analysis relies on discrete inequalities for the underlying energy, assuming a Lipschitz continuous gradient and either convexity or $μ$-strong convexity of the relevant terms. The resulting method is linearly implicit, yet it preserves the original energy-dissipation law, guarantees unique solvability, ensures boundedness of numerical solutions, and admits an a priori error estimate, provided that the time step is sufficiently small. To the best of our knowledge, this is the first linearly implicit finite difference scheme for the Swift--Hohenberg equation for which all of these properties are established.
