Nonlinear ion-acoustic cnoidal waves in a dense relativistic degenerate magnetoplasma.
Nonlinear ion-acoustic cnoidal waves in a dense relativistic degenerate magnetoplasma.
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DOI：
10.1103/physreve.91.033105
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发表时间：
2015-03
期刊：
影响因子：
--
通讯作者：
E. F. El-Shamy
中科院分区：
文献类型：
--
作者：
E. F. El-Shamy
研究了由相对论简并电子和非简并冷离子组成的致密相对论简并磁等离子体中非线性周期离子声波（即离子声波椭圆余弦波）的复杂图案和传播特性。利用约化摄动法和适当的非线性周期波边界条件，导出了非线性修正的Korteweg-de弗里斯（KdV）方程，并分析了其椭圆余弦波。用Sagdeev势方法数值求解了非线性离子-声椭圆余弦波和孤立波。研究了非线性修正KdV方程的非线性离子-声椭圆余弦波的解析解和数值模拟。显然，它被发现的特征（振幅和宽度）的非线性离子声学椭圆余弦波的等离子体数密度，离子回旋频率和方向余弦成正比。数值结果适用于高密度天体物理的情况下，如在超密度白色矮星。这一研究将有助于理解含相对论简并电子冷离子的致密天体的性质。
The complex pattern and propagation characteristics of nonlinear periodic ion-acoustic waves, namely, ion-acoustic cnoidal waves, in a dense relativistic degenerate magnetoplasma consisting of relativistic degenerate electrons and nondegenerate cold ions are investigated. By means of the reductive perturbation method and appropriate boundary conditions for nonlinear periodic waves, a nonlinear modified Korteweg-de Vries (KdV) equation is derived and its cnoidal wave is analyzed. The various solutions of nonlinear ion-acoustic cnoidal and solitary waves are presented numerically with the Sagdeev potential approach. The analytical solution and numerical simulation of nonlinear ion-acoustic cnoidal waves of the nonlinear modified KdV equation are studied. Clearly, it is found that the features (amplitude and width) of nonlinear ion-acoustic cnoidal waves are proportional to plasma number density, ion cyclotron frequency, and direction cosines. The numerical results are applied to high density astrophysical situations, such as in superdense white dwarfs. This research will be helpful in understanding the properties of compact astrophysical objects containing cold ions with relativistic degenerate electrons.