arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1804.00652nlin.PSnlin.SIphysics.flu-dyn
收藏

强相互作用孤立子气体与反常波的形成

Strongly interacting soliton gas and formation of rogue waves

A. A. Gelash, D. S. Agafontsev

摘要:

在聚焦一维非线性薛定谔(NLS)方程的框架下,数值研究了(统计上)均匀孤子气体的性质与孤子密度(与单位长度上的孤子数成正比)和孤子速度的关系.为了模拟这种气体,我们使用N-孤子解(N-SS)与$N\sim 100$,我们产生的具体实施的敷料方法结合100位数的算法。我们研究的主要统计特性,特别是动能和势能,峰度,波作用谱和概率密度函数(PDF)的波强度。我们表明,在小孤子密度的情况下的动能和势能,以及峰度,是很好地描述了由解析关系推导而不考虑孤子相互作用。随着孤子密度和速度的增加,孤子相互作用增强,我们观察到这些关系的偏差增加,导致所有这三个特性的绝对值增加。波作用谱是平滑的,在大的波数下接近指数衰减,并随着孤子密度和速度的增加而加宽。对于稀薄孤子气体,波强度的概率密度函数与指数(瑞利)概率密度函数有很大的偏差,在孤子之间的基本相互作用所对应的密度下,波强度的概率密度函数更接近指数(瑞利)概率密度函数。孤立子气体中出现的流氓波是多孤立子碰撞,但其中一些具有与不同阶数的Peregrine解非常相似的空间轮廓。我们提出的三孤子碰撞的例子,即使是最大振幅的时间行为是非常好的近似的二阶游隼解决方案。

英文摘要:

We study numerically the properties of (statistically) homogeneous soliton gas depending on soliton density (proportional to number of solitons per unit length) and soliton velocities, in the framework of the focusing one-dimensional Nonlinear Schr{ö}dinger (NLS) equation. In order to model such gas we use N-soliton solutions (N-SS) with $N\sim 100$, which we generate with specific implementation of the dressing method combined with 100-digits arithmetics. We examine the major statistical characteristics, in particular the kinetic and potential energies, the kurtosis, the wave-action spectrum and the probability density function (PDF) of wave intensity. We show that in the case of small soliton density the kinetic and potential energies, as well as the kurtosis, are very well described by the analytical relations derived without taking into account soliton interactions. With increasing soliton density and velocities, soliton interactions enhance, and we observe increasing deviations from these relations leading to increased absolute values for all of these three characteristics. The wave-action spectrum is smooth, decays close to exponentially at large wavenumbers and widens with increasing soliton density and velocities. The PDF of wave intensity deviates from the exponential (Rayleigh) PDF drastically for rarefied soliton gas, transforming much closer to it at densities corresponding to essential interaction between the solitons. Rogue waves emerging in soliton gas are multi-soliton collisions, and yet some of them have spatial profiles very similar to those of the Peregrine solutions of different orders. We present example of three-soliton collision, for which even the temporal behavior of the maximal amplitude is very well approximated by the Peregrine solution of the second order.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑