天体物理圆盘中非线性偏心波的聚焦。II。紧绕波的激励和阻尼
Focusing of nonlinear eccentric waves in astrophysical discs. II. Excitation and damping of tightly-wound waves
摘要：
在本文中，我开发了一个非线性理论的紧缠绕（高扭曲）偏心波在天体物理光盘，平均拉格朗日方法的基础上的Whitham。粘性耗散包括在理论中使用的伪拉格朗日。这项工作是由Lee \& Goodman开发的理论扩展到3D圆盘，增加了粘度。我确认，线性紧绕偏心波是超稳定的，并激发的剪切粘度的存在下，并显示这持续弱非线性波。我发现波阻尼剪切粘度时，波变得足够的非线性，结果以前发现在颗粒盘。此外，我比较这个模型的结果，最近的模拟偏心波传播的内部区域的黑洞光盘，并表明，传入偏心波可以强烈阻尼附近的边缘稳定的轨道，导致在一个近圆形的光盘具有较强的方位角变化的光盘密度。
英文摘要：
In this paper I develop a nonlinear theory of tightly-wound (highly twisted) eccentric waves in astrophysical discs, based on the averaged Lagrangian method of Whitham. Viscous dissipation is included in the theory by use of a pseudo-Lagrangian. This work is an extension of the theory developed by Lee \& Goodman to 3D discs, with the addition of viscosity. I confirm that linear tightly-wound eccentric waves are overstable and are excited by the presence of a shear viscosity and show this persists for weakly nonlinear waves. I find the waves are damped by shear viscosity when the wave become sufficiently nonlinear, a result previously found in particulate discs. Additionally I compare the results of this model to recent simulations of eccentric waves propagating in the inner regions of black hole discs and show that an ingoing eccentric wave can be strongly damped near the marginally stable orbit, resulting in a nearly circular disc with a strong azimuthal variation in the disc density.
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。
