The power series in time of the solution to the one-dimensional Vlasov-Poisson equation
Abstract
A small time solution method for the one-dimensional Vlasov-Poisson equation through expanding the solution as a power series in time and calculating the coefficients is here presented. The coefficients in this power series, which are functions of the space variable x and the speed v, are obtained using a recursion relation. The fourth-order approximation is calculated and is compared with the first-order approximate solution obtained using the method of characteristics, both evaluated at very small time scales or times very close to zero (t ~ 0). By analyzing the function defined as the difference of the two functions for some given time, we conclude that for t ~ 0.01, the absolute difference between the two solutions is of order 10-3 only. This is strong evidence that the power series expansion of the solution f in t is convergent for t<<1.