Parallelization of a Vlasov-Maxwell solver in four-dimensional phase space

We present a parallelized algorithm for solving the time-dependent Vlasov-Maxwell system of equations in the four-dimensional phase space (two spatial and velocity dimensions). One Vlasov equation is solved for every particle species, from which charge and current densities are calculated for the Maxwell equations. The paral-lelization is divided into two different layers. For the first layer, each plasma species is given its own processor group. On the second layer, the distribution function is domain decomposed on its dedicated resources. By separating the communication and calculation steps, we have met the design criteria of good speedup and simplicity in the implementation