Second-order implicit–explicit scheme for the Gray–Scott model

A second-order scheme for the Gray–Scott (GS) model used to describe the pattern formation is studied. The linear part of the GS equation for the time derivative and the viscous terms is discretized implicitly, while the other (or nonlinear) part of the GS equation explicitly. Galerkin finite element approximation methods are presented and analyzed, as well as methods for solving the resulting system of equations. The optimal L²$L^2$-norm error estimates are derived. Numerical experiments are presented.