A high order semi-Lagrangian discontinuous Galerkin method for Vlasov-Poisson simulations without operator splitting
For computational plasma physicists, this method offers a more efficient and accurate approach to Vlasov-Poisson simulations by eliminating splitting errors and enabling large time steps.
This paper develops a high-order semi-Lagrangian discontinuous Galerkin method for Vlasov-Poisson simulations without operator splitting, achieving up to third-order accuracy in space and time, local mass conservation, and positivity preservation. The method demonstrates significant CPU savings compared to the classical Runge-Kutta DG method on benchmark problems like Landau damping and two-stream instabilities.
In this paper, we develop a high order semi-Lagrangian (SL) discontinuous Galerkin (DG) method for nonlinear Vlasov-Poisson (VP) simulations without operator splitting. In particular, we combine two recently developed novel techniques: one is the high order non-splitting SLDG transport method [Cai, et al., J Sci Comput, 2017], and the other is the high order characteristics tracing technique proposed in [Qiu and Russo, J Sci Comput, 2017]. The proposed method with up to third order accuracy in both space and time is locally mass conservative, free of splitting error, positivity-preserving, stable and robust for large time stepping size. The SLDG VP solver is applied to classic benchmark test problems such as Landau damping and two-stream instabilities for VP simulations. Efficiency and effectiveness of the proposed scheme is extensively tested. Tremendous CPU savings are shown by comparisons between the proposed SL DG scheme and the classical Runge-Kutta DG method.