Nonlinear damped partial differential equations and their uniform discretizations
For researchers in numerical analysis and PDEs, this work provides a unified framework for designing structure-preserving discretizations that maintain optimal energy decay, addressing a known bottleneck in numerical simulation of damped systems.
The paper establishes sharp energy decay rates for a class of nonlinearly damped PDEs and designs discretization schemes that preserve these rates uniformly with respect to discretization parameters by adding numerical viscosity. Results cover Schrödinger, wave, and plate equations with nonlinear damping.
We establish sharp energy decay rates for a large class of nonlinearly first-order damped systems, and we design discretization schemes that inherit of the same energy decay rates, uniformly with respect to the space and/or time discretization parameters, by adding appropriate numerical viscosity terms. Our main arguments use the optimal-weight convexity method and uniform observability inequalities with respect to the discretization parameters. We establish our results, first in the continuous setting, then for space semi-discrete models, and then for time semi-discrete models. The full discretization is inferred from the previous results. Our results cover, for instance, the Schrödinger equation with nonlinear damping, the nonlinear wave equation, the nonlinear plate equation, as well as certain classes of equations with nonlocal terms.