Abstract—

Modulational collapse of a wave pulse in a complex nonlinear plasma described by a complex nonlinear Schrödinger equation (CNSE) including the effects of viscous heating and nonlinear damping, and the adjusting by an external potential are investigated. Theoretical and numerical results reveal that the original pulse first suffers modulational instability, the growth rate of the modulational instability increases with the increase of viscous heating, but it is not sensitive to the nonlinear damping. The instability induces the self-similar collapsing, then the fields rapidly transform into a turbulent state with short-wavelength modes. The results are explained in terms of the evolution of the total energy, which can become invariant during the evolution even though the system is nonconservative. The external potential can delay the self-defocusing process of the pulse. Those results can apply to the phenomena described by the CNSE.

中文翻译：

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复杂非线性等离子体中的外部电位调制塌陷和调节

摘要-

研究了由复杂非线性Schrödinger方程（CNSE）描述的复杂非线性等离子体中波脉冲的调制崩溃，其中包括粘性加热和非线性阻尼的影响，以及通过外部电势进行的调节。理论和数值结果表明，原始脉冲首先遭受调制不稳定性，调制不稳定性的增长率随着粘性加热的增加而增加，但对非线性阻尼不敏感。不稳定性引起自相似的塌陷，然后场以短波长模式迅速转变为湍流状态。用总能量的演化来解释结果，即使系统是非保守的，总能量在演化过程中也可能不变。外部电势会延迟脉冲的自散焦过程。这些结果可以适用于CNSE描述的现象。