We introduce two exponential-type integrators for the "good" Bousinessq equation. They are of orders one and two, respectively, and they require lower regularity of the solution compared to the classical exponential integrators. More precisely, we will prove first-order convergence in H r for solutions in H r+1 with r > 1/2 for the derived first-order scheme. For the second integrator, we prove second-order convergence in H r for solutions in H r+3 with r > 1/2 and convergence in L 2 for solutions in H 3 . Numerical results are reported to illustrate the established error estimates. The experiments clearly demonstrate that the new exponential-type integrators are favorable over classical exponential integrators for initial data with low regularity.
IntroductionConsider the "good" Boussinesq (GB) equation [4] z tt + z xxxx − z xx − (z 2 ) xx = 0, (1.1) which was originally introduced as a model for one-dimensional weakly nonlinear dispersive waves in shallow water. Similar to the well-known Korteweg-de Vries (KdV) equation and the cubic Schrödinger equation, the GB equation is one of the important models describing the interaction between nonlinearity and dispersion. The GB equation has been widely applied in many areas, e.g., plasma, coastal engineering, hydraulics studies, elastic crystals and so on.The GB equation and its various extensions have been extensively analyzed in the literature. For the well-posedness, we refer to [10-12, 17, 23, 26] and references therein. For the interaction of solitary waves, we refer to [21,22]. Many numerical methods have been developed for solving the GB equation, such as finite difference methods (FDM) [5,24], Petrov-Galerkin methods [21], mesh free methods [8], Fourier spectral methods [6,7,27] and operator splitting methods [28,29]. Regarding the numerical analysis for the GB equation,