“…The WG method is first introduced by Wang and Ye [17,18] for the second-order elliptic equations, and a stabilizer term is added to WG-FEM in order to enforce the connection of discontinuous functions across element boundaries [10,11]. Then the WG method finds applications in diverse areas including elliptic equations [9,27], parabolic equations [30,31,34,35], second-order linear wave equation [6], reaction-diffusion equations [8], Stokes equations [13,16,32], Maxwell equations [12,14,20], biharmonic equation [33], Cahn-Hilliard-Cook equation [5], stochastic parabolic equations [36,37], eigenvalue problems [28,29], and so on. Nevertheless, the stabilizer makes the finite element formulations and programming complex.…”