阿尔芬高斯波包演化为阿尔芬孤波的条件及阿尔芬波的调制不稳定性判据

通过计算阿尔芬孤波的运动常数C1，发现消零孤波（vanishing soliton）均满足C1≤0，结合其他研究者关于阿尔芬波调制不稳定性的定性结论，提出阿尔芬波包演化为孤波的条件为C1≤0.数值计算结果支持了这个猜测.同时计算结果还表明,最终演化成的孤波数目既不完全依赖于积分常数C0，也不完全依赖于C1 .文献［1］和［2］所得的结论源于演化时间太短.通过与其他文献比较，发现C1≤0还可以作为阿尔芬波的调制不稳定性判据. 关键词： 阿尔芬波 derivative nonlinear Schrdinger方程 调制不稳定性判据 孤立波 高斯波包

Condition of Alfven Gauss wave-packet evolvement to solitons and criterion of Alfven wave modulation instability

By analyzing the integral constant C1 of Alfven solitons, the condition of Alfven Gaussian wave-packets evolvement to solitary waves is put forward as C1≤0. This hypothesis is also confirmed by numerical simulation results. Furthermore,simulation results show that the number of evolving solitons does not depend only on integral constant C0 or C1. The conclusions in Refs. ［1］ and ［2］ result from the shorter evolving time. Comparing with other papers, we find that C0≤0 can be used as a criterion of Alfven wave modulation instability.