TY - JOUR T1 - An Efficient EXCMG-Newton Method Combined with Fourth-Order Compact Schemes for Semilinear Poisson Equations AU - Wu , Pinxia AU - Pan , Kejia AU - Ling , Weiwei AU - He , Dongdong JO - East Asian Journal on Applied Mathematics VL - 1 SP - 119 EP - 139 PY - 2023 DA - 2023/01 SN - 13 DO - http://doi.org/10.4208/eajam.240222.210722 UR - https://global-sci.org/intro/article_detail/eajam/21305.html KW - Semilinear Poisson equation, fourth-order compact scheme, EXCMG-Newton method, high efficiency, bi-quartic interpolation. AB -

A fast solver for nonlinear systems arising from fourth-order compact finite difference schemes for two-dimensional semilinear Poisson equations is constructed. Applying the extrapolation and bi-quartic interpolation to two numerical solutions from the previous two levels of grids, we determine a suitable initial guess for the Newton iterations on the next finer grid. It is fifth-order accurate, which substantially reduces the number of Newton iterations required. Moreover, an extrapolated solution of sixth-order accuracy can be easily constructed on the whole fine grid. Numerical results suggest that the method is much more efficient than the existing multigrid methods for semilinear problems.