学术报告（杨雄锋 12.16）

In this talk, I will present the study of the long wave approximation to the Euler-Poisson system of the ion-acoustic wave in cold plasma according to the spatial-temporal scale and the amplitude of waves. We first justify rigorously that in the long-wave limit, the one-way propagating solutions of the Euler-Poisson system are well approximated by the unidirectional solutions of the Burgers-or KdV equation with the different parameter scales. We then demonstrate that the solutions could be convergent to two wave packets in opposite directions, where each wave packet involves independently as a solution of the Burgers-or KdV equation.